Ultra-Slow Light and Enhanced Nonlinear Optical Effects in a Coherently Driven Hot Atomic G

第43卷㊀第1期2022年1月发㊀光㊀学㊀报CHINESE JOURNAL OF LUMINESCENCEVol.43No.1Jan.,2022㊀㊀收稿日期:2021-10-25;修订日期:2021-11-11㊀㊀基金项目:国家重点研发计划(2017YFB0404104);国家自然科学基金(61974139);北京自然科学基金(4182063)资助项目Supported by National Key R&D Program of China (2017YFB0404104);National Natural Science Foundation of China (61974139);Beijing Natural Science Foundation(4182063)文章编号:1000-7032(2022)01-0001-07量子垒高度对深紫外LED 调制带宽的影响郭㊀亮1,2,郭亚楠1,2,羊建坤1,2,闫建昌1,2,王军喜1,2,魏同波1,2∗(1.中国科学院半导体研究所半导体照明研发中心,北京㊀100083;2.中国科学院大学材料与光电研究中心,北京㊀100049)摘要:AlGaN 基深紫外LED 由于具有高调制带宽和小芯片尺寸,在紫外光通信领域受到越来越多的关注㊂本研究通过改变生长AlGaN 量子垒层的Al 源流量,生长了三种具有不同量子垒高度的深紫外LED,研究了量子垒高度对深紫外LED 光电特性和调制特性的影响㊂研究发现,随着量子垒高度的增加,深紫外LED 的光功率出现先增加后减小的趋势,量子垒中Al 组分为55%的深紫外LED 的光功率相比50%和60%的深紫外LED 提升了近一倍㊂载流子寿命则出现先减小后增大的趋势,且发光峰峰值波长逐渐蓝移㊂APSYS 模拟表明,随着量子垒高度增加,量子垒对载流子的束缚能力增强,电子空穴波函数空间重叠增加,载流子浓度和辐射复合速率增加;但进一步增加量子垒高度又会由于电子泄露,空穴浓度降低,从而辐射复合速率降低㊂量子垒中Al 组分为55%的深紫外LED 的-3dB 带宽达到94.4MHz,高于量子垒Al 组分为50%和60%的深紫外LED㊂关㊀键㊀词:紫外光通信;深紫外发光二极管;多量子阱层;调制带宽;发光功率中图分类号:TN383+.1;TN929.12㊀㊀㊀文献标识码:A㊀㊀㊀DOI :10.37188/CJL.20210331Effect of Barrier Height on Modulation Characteristics ofAlGaN-based Deep Ultraviolet Light-emitting DiodesGUO Liang 1,2,GUO Ya-nan 1,2,YANG Jian-kun 1,2,YAN Jian-chang 1,2,WANG Jun-xi 1,2,WEI Tong-bo 1,2∗(1.Research and Development Center for Semiconductor Lighting Technology ,Institute of Semiconductors ,Chinese Academy of Sciences ,Beijing 100083,China ;2.Center of Materials Science and Optoelectronics Engineering ,University of Chinese Academy of Sciences ,Beijing 100049,China )∗Corresponding Author ,E-mail :tbwei @Abstract :AlGaN-based deep ultraviolet LED has attracted more and more attention in ultravioletcommunication due to its high modulation bandwidth and small chip size.In this study,AlGaN-based deep ultraviolet LEDs with varied Al composition of 50%,55%,60%in quantum barriers are fabricated.The effect of barrier height on the photoelectric and modulation characteristics of deep ultraviolet LEDs is studied.It is found that the optical power and external quantum efficiency (EQE)of the deep ultraviolet LED increase first and then decreased,and carrier lifetime decreases first and then increases as the quantum barrier height increases.The peak wavelength of the spectra shows a blue-shift.APSYS simulation revealed that the spacial overlap between the wave function of electron and hole is enhanced as Al composition increases.But further increase on barrier height will lead to current leakage which reduces the radiation recombination rate and carrier density in . All Rights Reserved.2㊀发㊀㊀光㊀㊀学㊀㊀报第43卷quantum well layer.The-3dB bandwidth of deep ultraviolet LED with55%Al composition inquantum barrier is measured to be94.4MHz,higher than those with50%and60%Al composition in quantum barrier.Key words:ultraviolet communication;deep ultraviolet light-emitting diodes;multiple-quantum-well layer;modula-tion bandwidth;optical power1㊀引㊀㊀言随着深紫外LED和日盲探测器的发展,紫外光通信受到越来越多的关注㊂紫外光通信利用紫外光传输信号,该信号可以被漂浮在空气中的微粒和气溶胶等散射和反射,实现非视距通信[1-2]㊂紫外光通信中使用的紫外光也称为日盲紫外光,它在光谱中位于200~280nm之间[3-4]㊂当太阳辐射穿过大气层时,会被空气中的水蒸气㊁二氧化碳㊁氧气㊁臭氧㊁悬浮颗粒和其他气体分子强烈散射㊁吸收或反射,从而导致太阳光谱不连续㊂在所有分子和粒子中,仅占大气0.01%~0.1%的臭氧在紫外光谱中具有很强的吸收带,从而使得到达地表的太阳光中日盲紫外光含量极少,这则为紫外光通信提供了低背景噪声的通信环境[5]㊂同时,紫外光通信还具有高保密性㊁无需频段许可㊁抗干扰能力强等优势,这使得紫外光通信在军事领域具有重要应用价值㊂紫外光源作为紫外光通信系统中重要的组成部分,其光功率决定了紫外光通信系统的传输距离,而其带宽决定了通信速率的上限[6]㊂紫外光通信系统中最常用的三种光源包括气体放电灯㊁激光器和LED㊂气体放电灯制造成本低㊁输出功率大,激光器的光线相干性高㊁单色性好㊁发散性低,然而这两种光源都存在体积大㊁功耗大㊁调制速率低的缺点㊂AlGaN基LED由于具有更高的调制带宽和更小的芯片尺寸,在紫外光通信中得到了越来越广泛的应用[7-9]㊂近年来,越来越多的研究团体开始研究基于深紫外LED作为光源的紫外光通信㊂Alkhazragi等基于商用发光波长为279nm的深紫外LED实现了1m链路上通信速率为2.4Gbps的紫外光通信系统,测得调制带宽为170MHz[10]㊂2018年,Kojima等基于调制带宽为153MHz㊁发光波长为280nm的深紫外LED,在1.5m链路上实现了1.6Gbps的通信速率[11]㊂2019年,He等制备了AlGaN基262nm深紫外Micro-LED阵列,在71 A/cm2电流密度下,测得调制带宽达到了438 MHz,在0.3m链路上实现了高达1.1Gbps的数据传输速率[12]㊂Zhu等制备了100μm深紫外Micro-LED,在400A/cm2电流密度下,测得调制带宽为452.53MHz[13]㊂尽管AlGaN基深紫外LED在紫外光通信中已经得到了广泛应用,但目前大部分研究仍集中在LED芯片工艺的改进上㊂关于深紫外LED外延结构对调制特性的影响的研究几乎处于空白状态㊂本研究通过改变生长AlGaN量子垒层时的Al源流量,控制了量子垒中Al组分分别为50%㊁55%和60%,生长了三种具有不同量子垒高度的深紫外LED,研究了量子垒高度对深紫外LED光电特性和调制特性的影响㊂并借助APSYS模拟和时间分辨光致发光光谱对实验结果进行了深入分析㊂2㊀实㊀㊀验2.1㊀样品制备实验中首先在c面蓝宝石衬底上生长1μm 厚的AlN缓冲层,然后在1130ħ下沉积20个周期的AlN(2nm)/Al0.6Ga0.4N(2nm)超晶格层㊂然后依次生长1.8μm厚Si掺杂浓度为3ˑ1018 cm-3的n-Al0.61Ga0.39N层,5个周期Al0.4Ga0.6N图1㊀紫外外延片结构示意图Fig.1㊀Wafer structure of ultraviolet LED. All Rights Reserved.㊀第1期郭㊀亮,等:量子垒高度对深紫外LED调制带宽的影响3㊀(3nm)/Al0.5/0.55/0.6Ga0.5/0.45/0.4N(12nm)多量子阱层,50nm厚的Mg掺杂p-Al0.6Ga0.4N电子阻挡层,30nm厚p-Al0.5Ga0.5N层以及150nm厚Mg 掺杂浓度为1ˑ1018cm-3的p-GaN层㊂随后,在800ħ氮气气氛下退火20min以激活Mg受主㊂对生长得到的深紫外LED外延片使用标准紫外流片工艺,制备了倒装结构深紫外LED,芯片尺寸为250μmˑ550μm,图1为外延片结构示意图㊂2.2㊀样品表征LED光功率测试采用的是远方光电公司HAAS-2000高精度快速光谱辐射计,该设备光谱范围为200~2550nm㊂光致发光光谱测试采用215nm紫外激光器作为激发光源,激光功率为31 mW,所用光栅线密度为1200l/mm,测试波长范围为240~320nm,步长为0.2nm,积分时间为1.0s,测试环境温度为295K㊂带宽测试系统采用安捷伦E5061B型网络分析仪,其扫描频率范围为5Hz~3GHz,可覆盖氮化物LED的频率响应范围㊂直流偏置源采用Keithley2420作为电流源,该电流源最大输出电流为3A,最大输出电压为60 V㊂紫外探测器采用Thorlabs公司APD430A2/M 型硅基雪崩探测器,可探测波长范围是200~ 1000nm,可覆盖整个UVC波段㊂图2为实验中使用的带宽测试系统示意图㊂图2㊀带宽测试系统示意图Fig.2㊀Diagram of bandwidth testing system3㊀结果与讨论3.1㊀电致发光光谱图3是3种不同量子垒高度深紫外LED的EL测试结果㊂在20mA电流下,量子垒中Al组分为50%㊁55%和60%的深紫外LED的峰值波长分别为280.4,276.5,274.0nm,可以看出随着量子垒中Al组分的增加,深紫外LED的峰值波长逐渐蓝移㊂这是因为随着量子垒高度增加,量子阱对电子空穴的束缚能力增加,电子和空穴波函数的空间分离减小,量子限制效应增强,从而导致蓝移㊂同时可以看出,随着电流从20mA增加到100mA,深紫外LED的峰值波长逐渐红移㊂Al组分为50%的深紫外LED的峰值波长红移了1.2nm,Al组分为55%的深紫外LED的峰值波长红移了2nm,Al组分为60%的深紫外LED的峰值波长红移了1nm㊂同时LED的发光峰半高宽也逐渐展宽,Al组分为50%的深紫外LED的半高宽从9.9nm展宽到10.8nm,Al组分为55%的深紫外LED的半高宽从11.3nm展宽到12nm, Al组分为60%的深紫外LED的半高宽从10.7nm图3㊀量子垒中Al组分为50%(a)㊁55%(b)㊁60%(c)的深紫外LED的EL光谱随电流的变化㊂Fig.3㊀EL spectra of ultraviolet LED with Al composition of 50%(a),55%(b),60%(c)in quantum barrierunder varied currents.. All Rights Reserved.4㊀发㊀㊀光㊀㊀学㊀㊀报第43卷展宽到11.7nm㊂这是因为根据焦耳定律,随着电流增加,单位时间内产生的热量增加㊂根据能带宽度和温度的关系,深紫外LED的能带宽度会随着温度升高而线性减小,从而导致发光波长红移[14]㊂热量的增加还会导致量子限制斯塔克效应增强,从而导致半高宽增加[15]㊂3.2㊀光功率对3种不同量子垒高度的深紫外LED芯片进行光电测试,得到不同测试电流下的光功率测试结果,如图4所示㊂可以看出光功率随着量子图4㊀量子垒中Al组分为50%㊁55%㊁60%的深紫外LED 的光功率随电流的变化㊂Fig.4㊀Optical power of ultraviolet LED with Al composition of50%,55%,60%in quantum barrier under var-ied currents.垒高度的增加,出现先增大后减小的趋势㊂这是因为随着量子垒高度的增加,量子阱对电子空穴的束缚能力增强,使得电子空穴浓度增加,从而导致光功率增大㊂但进一步增加量子垒高度,会导致电子阻挡层对过冲电子的束缚能力减弱,过冲电子与p型区的空穴复合,导致空穴电流减小,最终导致光功率降低[16]㊂3.3㊀APSYS模拟我们使用APSYS软件对不同量子垒高度的AlGaN基深紫外LED的能带结构进行了模拟㊂模拟时,深紫外LED的注入电流为62.5mA,器件尺寸为250μmˑ250μm,从下到上为蓝宝石衬底㊁AlN缓冲层㊁n-Al0.55Ga0.45N层㊁有源区㊁p-Al0.65Ga0.35N电子阻挡层㊁p-Al0.55Ga0.45N层㊁p-GaN层㊂有源区由5个量子阱层和6个量子垒层组成,阱层为2nm厚的Al0.45Ga0.55N,垒层为10nm厚的Al0.5/0.55/0.6Ga0.5/0.45/0.4N㊂不同量子垒高度的AlGaN基的深紫外LED的能带结构如图5(a)㊁(b)㊁(c)所示㊂可以看出,随着量子垒高度的增加,电子和空穴的波函数空间分离逐渐减小,我们进一步对其辐射复合速率进行了模拟,模拟结果如图5(d)所示㊂辐射复合速率随着量子垒高度出现了先增加后减小的趋势㊂这是因为随着量子垒高度的增加,量子垒对载流子的束缚作图5㊀量子垒中Al组分为50%(a)㊁55%(b)㊁60%(c)的深紫外LED的能带结构示意图;(d)量子垒中Al组分为50%㊁55%和60%的深紫外LED的辐射复合速率分布示意图㊂Fig.5㊀Band structure of ultraviolet LED with Al composition of50%(a),55%(b),60%(c)in quantum barrier.(d)Ra-diation recombination rate of ultraviolet LED with Al composition of50%,55%and60%in quantum barrier.. All Rights Reserved.㊀第1期郭㊀亮,等:量子垒高度对深紫外LED调制带宽的影响5㊀用增加,使得量子阱内的载流子浓度增大,同时由于电子和空穴的空间波函数重叠增加,辐射复合所占的比重也会增加,从而辐射复合速率增大㊂但进一步增加量子垒高度又会由于电子泄漏,从而导致辐射复合速率减小[17-18]㊂3.4㊀时间分辨光致发光光谱我们对不同量子垒高度的深紫外LED进行了时间分辨光致发光光谱(TRPL)测试㊂不同量子垒高度深紫外LED的TRPL测试结果如图6所示㊂通过对曲线的衰减部分使用以下公式进行双衰减指数拟合[19]:I(t)=A1e-ττ1+A2e-ττ2,(1)其中τ1满足1/τ1=1/τnr+1/τ2,τnr为非辐射复合载流子寿命,τ2为辐射复合载流子寿命㊂量子垒中Al组分为50%㊁55%和60%的深紫外LED的载流子寿命分别为432,276,352ps㊂可以看出载流子寿命随着量子垒中Al组分的增加出现先减小后增大的趋势㊂图6㊀量子垒中Al组分为50%㊁55%㊁60%的深紫外LED的TRPL光谱随电流的变化㊂Fig.6㊀TRPL spectra of ultraviolet LED with Al composition of50%,55%,60%in quantum barrier.热平衡状态下,pn结中的载流子复合速率可以由以下公式得到:R=B(N0+Δn)(P0+Δn)-BN0P0,(2)其中B为复合常数,N0为电子浓度,P0为空穴浓度,Δn为过剩载流子浓度㊂经整理后可以得到如下公式:R=B(N0+P0+Δn)Δn,(3)由于在p型区中,P0远大于N0,因此上述公式可以进一步简化为:R=B(P0+Δn)Δn,(4)载流子寿命可以由以下公式表示:τ=Δn R=1B(P0+Δn),(5)由于载流子寿命和辐射复合速率成反比,随着量子垒高度增加,量子垒对载流子的束缚作用增强,辐射复合速率增加,载流子寿命因此减小㊂但进一步增加量子垒高度又会由于电子泄漏,导致辐射复合速率减小,载流子寿命增加[20]㊂3.5㊀调制带宽测试在60mA电流下,测试得到了深紫外LED的频率响应结果如图7所示㊂量子垒中Al组分为50%㊁55%和60%的深紫外LED的-3dB带宽分别为75.0,94.4,82.0MHz㊂深紫外LED的调制带宽随着量子垒高度的增加,出现了先增加后减小的趋势㊂LED的调制带宽主要受到载流子寿命和RC 时间常数决定,并且对于常规尺寸LED,其主要受载流子辐射复合寿命决定㊂载流子辐射复合寿命决定了发光强度在交变信号下的上升和下降时间,也决定了光功率随交变信号变化反应的快慢㊂两者之间满足以下关系[21]:f-3dB=12πτBJ qd,(6)其中f-3dB为LED的-3dB带宽,B为双分子复合系数,J为电流密度,q为元电荷,d为有源区厚度㊂载流子寿命越短,则光子随外电流变化反应的速度越快,从而调制带宽越高㊂这一结果也与3.4中载流子寿命的结果相吻合㊂图7㊀量子垒中Al组分为50%㊁55%㊁60%的深紫外LED 的频率响应图㊂Fig.7㊀Frequency response of ultraviolet LED with Al com-position of50%,55%,60%in quantum barrier. 4㊀结㊀㊀论本文研究了量子垒高度对深紫外LED光电. All Rights Reserved.6㊀发㊀㊀光㊀㊀学㊀㊀报第43卷特性和调制特性的影响,制备了3种具有不同量子垒高度的深紫外LED㊂研究发现,随着量子垒高度的增加,深紫外LED的光功率和外量子效率出现先增加后减小的趋势,载流子寿命则出现先减小后增大的趋势,EL光谱发光峰峰值波长逐渐蓝移㊂最后,我们使用基于网络分析仪的带宽测试系统对不同量子垒高度的深紫外LED进行了带宽测试,测得量子垒中Al组分为50%㊁55%和60%的深紫外LED的-3dB带宽分别为75.0, 94.4,85.0MHz㊂本文专家审稿意见及作者回复内容的下载地址: /thesisDetails#10.37188/ CJL.20210331.参㊀考㊀文㊀献:[1]UAN R Z,MA J S.Review of ultraviolet non-line-of-sight communication[J].China Commun.,2016,13(6):63-75.[2]DROST R J,SADLER B M.Survey of ultraviolet non-line-of-sight communications[J].Semicond.Sci.Technol.,2014,29(8):084006-1-11.[3]SHAW G A,NISCHAN M L,IYENGAR M A,et al.NLOS UV communication for distributed sensor systems[C].Pro-ceedings of SPIE4126,Integrated Command Environments,San Diego,CA,United States,2000:83-96.[4]KHAN A,BALAKRISHNAN K,KATONA T.Ultraviolet light-emitting diodes based on group three nitrides[J].Nat.Photonics,2008,2(2):77-84.[5]VAVOULAS A,SANDALIDIS H G,CHATZIDIAMANTIS N D,et al.A survey on ultraviolet C-band(UV-C)communica-tions[J].IEEE Commun.Surv.Tutor.,2019,21(3):2111-2133.[6]GUO L,GUO Y N,WANG J X,et al.Ultraviolet communication technique and its application[J].J.Semicond.,2021,42(8):081801.[7]ZHANG H,HUANG C,SONG K,et positionally gradedⅢ-nitride alloys:building blocks for efficient ultraviolet op-toelectronics and power electronics[J].Rep.Prog.Phys.,2021,84(4):044401-1-28.[8]HUANG C,ZHANG H C,SUN H D.Ultraviolet optoelectronic devices based on AlGaN-SiC platform:towards monolithicphotonics integration system[J].Nano Energy,2020,77:105149.[9]YU H B,MEMON M H,WANG D H,et al.AlGaN-based deep ultraviolet micro-LED emitting at275nm[J].Opt.Lett.,2021,46(13):3271-3274.[10]ALKHAZRAGI O,HU F C,ZOU P,et al.Gbit/s ultraviolet-C diffuse-line-of-sight communication based on probabilistical-ly shaped DMT and diversity reception[J].Opt.Express,2020,28(7):9111-9122.[11]KOJIMA K,YOSHIDA Y,SHIRAIWA M,et al.1.6-Gbps LED-based ultraviolet communication at280nm in direct sun-light[C].Proceedings of the2018European Conference on Optical Communication,Rome,Italy,2018:1-3.[12]HE X Y,XIE E Y,ISLIM M S,et al.1Gbps free-space deep-ultraviolet communications based onⅢ-nitride micro-LEDsemitting at262nm[J].Photonics Res.,2019,7(7):B41-B47.[13]ZHU S J,QIU P J,QIAN Z Y,et al.2Gbps free-space ultraviolet-C communication based on a high-bandwidth micro-LEDachieved with pre-equalization[J].Opt.Lett.,2021,46(9):2147-2150.[14]BAUMGARTNER H,VASKURI A,KÄRHÄP,et al.Temperature invariant energy value in LED spectra[J].Appl.Phys.Lett.,2016,109(23):231103-1-4.[15]WANG T,NAKAGAWA D,WANG J,et al.Photoluminescence investigation of InGaN/GaN single quantum well and multi-ple quantum wells[J].Appl.Phys.Lett.,1998,73(24):3571-3573.[16]REN Z J,YU H B,LIU Z L,et al.Band engineering ofⅢ-nitride-based deep-ultraviolet light-emitting diodes:a review[J].J.Phys.D:Appl.Phys.,2020,53(7):073002.[17]GUTTMANN M,HÖPFNER J,REICH C,et al.Effect of quantum barrier composition on electro-optical properties of Al-GaN-based UVC light emitting diodes[J].Semicond.Sci.Technol.,2019,34(8):085007-1-6.[18]王玮东,楚春双,张丹扬,等.俄歇复合㊁电子泄漏和空穴注入对深紫外发光二极管效率衰退的影响[J].发光学报,2021,42(7):897-903.WANG W D,CHU C S,ZHANG D Y,et al.Impact of auger recombination,electron leakage and hole injection on efficiency . All Rights Reserved.㊀第1期郭㊀亮,等:量子垒高度对深紫外LED 调制带宽的影响7㊀droop for DUV LEDs [J].Chin.J.Lumin .,2021,42(7):897-903.(in Chinese)[19]ZHUANG Z,GUO X,LIU B,et al.Great enhancement in the excitonic recombination and light extraction of highly ordered InGaN /GaN elliptic nanorod arrays on a wafer scale [J].Nanotechnology ,2016,27(1):015301.[20]刘恩科,朱秉升,罗晋生.半导体物理学[M].第7版.北京:电子工业出版社,2008.LIU E K,ZHU B S,LUO J S.The Physics of Semiconductors [M].7th ed.Beijing:Publishing House of Electronics Indus-try,2008.(in Chinese)[21]ZHU S C,YU Z G,ZHAO L X,et al.Enhancement of the modulation bandwidth for GaN-based light-emitting diode by sur-face plasmons [J].Opt.Express ,2015,23(11):13752-13760.郭亮(1996-),男,江西吉安人,硕士研究生,2018年于合肥工业大学获得学士学位,主要从事通信用深紫外LED 的研究㊂E-mail:guoliang18@semi.ac.cn魏同波(1978-),男,山东潍坊人,博士,研究员,2007年于中国科学院半导体研究所获得博士学位,主要从事宽禁带半导体材料生长及器件制备的研究㊂E-mail:tbwei@. All Rights Reserved.。

第43卷第6期2022年6月Vol.43No.6June,2022发光学报CHINESE JOURNAL OF LUMINESCENCEA Stable UV Photodetector Based on n-ZnS/p-CuSCNNanofilm with High On/Off RatioWEI Yao-qi，QUAN Jia-le，ZHAO Qing-qiang，ZHOU Ming-chen，HAN San-can*（College of Materials and Chemistry，University of Shanghai for Science and Technology，Shanghai200093，China）*Corresponding Author，E-mail：mickey3can@Abstract：Herein，We fabricated a CuSCN nanofilm ultraviolet（UV）photodetector（PD）using an in situ growth method.When the bias is-1V and the incident light is350nm，the on/off ratio of the CuSCN PD is~94，and the rise/decay time is～1.41s/1.44s.However，such a device still cannot be called a high-performance photodetector.To improve the optoelectronic properties of CuSCN nanofilm further，we fabricated a UV photodetector based on n-ZnS/p-CuSCN composite nanofilm and analyzed its morphology，composition，and properties.The photocurrent and dark current of the ZnS/CuSCN UV photodetectors are1.22×10-5A and4.8×10-9A，respectively（at-1V，350nm）.The ZnS/CuSCN nanofilms on/off ratio of~2542and rise/decay time is0.47s/0.48s.Besides，the n-ZnS/p-CuSCN nanofilm UV PDs have the best responsivity and detectivity at350nm with5.17mA/W and1.32×1011Jones，re‑spectively.In addition，the n-ZnS/p-CuSCN composite film is stable at room temperature，which indicates its great potential as a high-performance UV photodetector.Key words：photodetector；p-n junction；ZnS/CuSCN；on/off ratioCLC number：TN23Document code：A DOI：10.37188/CJL.20220069一种基于n-ZnS/p-CuSCN纳米薄膜的高开关比和稳定性紫外光电探测器魏瑶琪，全家乐，赵庆强，邹明琛，韩三灿*（上海理工大学材料与化学学院，上海200093）摘要：通过原位生长法制备了一种CuSCN纳米薄膜紫外光电探测器，在-1V偏压下，入射光为350nm时，CuSCN紫外光电探测器的开关比～94，响应/恢复时间~1.41s/1.44s。

SonicWall SonicWave series wireless access points (APs) combinehigh-performance IEEE 802.11ac Wave 2 wireless technology with flexible deployment options. These APs can be managed via the cloud using SonicWall WiFi Cloud Manager (WCM) or through SonicWall’s industry-leading next-generation firewalls. 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The RTDMI engine of CaptureATP proactively detects and blocks massmarket, zero-day threats and unknownmalware by inspecting directly in memory.Because of the real-time architecture,SonicWall RTDMI technology is precise,minimizes false positives, and identifiesBenefits:• Enhanced user experience−802.11ac Wave 2−Auto channel selection−RF spectrum analysis−AirTime Fairness−Fast roaming• Best-in-class wireless security−Dedicated third scanning radio−Capture ATP and content filteringservice−Deep packet inspection technology−SSL/TLS decryption andinspection−Wireless intrusion detection andprevention• Intuitive cloud management−Alerts and rich analytics−Automatic firmware updates• Simplified firewall management−Auto-detection and provisioning−Wireless signal analysis tools−Single-pane-of-glass management• Zero-Touch Deployment powered bySonicWiFi app−Easy registration and onboarding−Auto-detection and auto-provisioning−App available on iOS and Android• Design with WiFi Planner−Advanced wireless site survey−Cloud-based tool• Ruggedized outdoor designSonicWave and SonicPoint Series Wireless Access PointsSecure, flexible, high-performance wireless solutionsSonicWave APs perform advancedsecurity services, including the Content Filtering Service (CFS) and Capture ATPsandbox service independently — even where firewalls are not deployed.Most SonicWave APs includes threeradios, where the third radio is dedicated to security and performs rogue APdetection, passive scanning and packet capturing. 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Durable and ReliableThe FDS1904 and FDS1904T offer durability for use in harsh maritime environments, complying with the conditions for temperature, humidity, and vibration as de ned in theIEC 60945 international standard for maritime navigation and radio communication equipment and systems. IP65 rating ensures they can withstand dust ingress and are protectedagainst low-pressure water jets. A coating is applied to make the electronic substrates moisture-proof and the cooling fan is easily accessible for exchanging purposes.Approval from Classification SocietiesThe monitors meet the requirements for major maritimeclassi cations with approvals for LR(UK), DNV GL (Norway /Germany), ABS (USA), and NK (Japan). Additional certi ca-tions are available on request.Long-Lasting LED BacklightThe monitors are equipped with an LED backlight. Compared to conventional CCFL backlights, LED backlights last longer and consume less power. They are also mercury-free for minimal impact on the environment.Calibrated for ECDISBacklight brightness, gamma, and RGB color settings arecalibrated at the factory so each monitor achieves accurate color reproduction for meeting the highly specialized requirements of ECDIS systems. Both monitors meet IEC 61174, IEC 62288, and IEC 62388 international standards for ECDIS and RADAR applications.Panel Mount Marine Monitors with LED Backlight for ECDIS / RADAR ApplicationsFDS1904 / FDS1904T19" Marine MonitorsWide Dimming RangeThe wide dimming range of less than 1 cd/m 2 up to 590 cd/m 2 (540 cd/m 2 for the FDS1904T) allows you to adjust to the appropriate brightness level for viewing during the day or at night.Clear ViewThe VA panel features wide viewing angles that minimize changes in contrast and gradation to maintain excellent visibility when the screen is viewed from the side. An AR coating is applied to reduce the amount of re ections on the screen for a clear display.Touch Panel ModelThe FDS1904T features a projected capacitive touch panel that accepts touch input from a bare hand or special stylus and supports multitouch operation. It is also highlyresistant to dust and water droplets to minimize unintend-ed input.Optical Bonding for High VisibilityOptional optical bonding is available for both models. Optical bonding signi cantly reduces re ective light for high visibility even when the screen is viewed in direct sunlight. A screen with optical bonding is also more resistant to applied pressure, giving it increased physical durability.FDS1904TFDS1904Additional Features24-Hour Use, 3-Year Warranty ECDIS IndicatorMarine Alarm BuzzerS P E C I F I C A T I O N SPlease visit the product pages on for information on ship classification.Dimensions (mm)Panel aperture dimensionsSCREW (5mm) x 6429100412 0.5D-SUB(OUT)D-SUB(IN)DVI DC-in AC-in USB("-T"only)MONITOR CONTROL PORT SERIAL ("-T"only)376.32(LCD Active area)378(Non-painting area)26.3426.3440652.4752.47301.06(L C D A c t i v e a r e a )303(N o n -p a i n t i n g a r e a )362(G L A S S -s i z e )74.54100360 0.5382 0.3180 0.2140 0.2180 0.2All product names are trademarks or registered trademarks of their respective companies.DuraVision and EIZO are registered trademarks of EIZO Corporation.Speci cations are subject to change without notice.153 Shimokashiwano, Hakusan, Ishikawa 924-8566 Japan Phone +81-76-277-6792 Fax +81-76-277-6793Copyright © 2017 EIZO Corporation. All rights reserved.Optional StandAn optional stand isavailable with the monitors which allows tilt position-ing from 0 - 60 degrees. The stand, when combined with the monitors,complies with the condi-tions for temperature,humidity, and vibration as de ned in IEC 60945. It also meets the requirements for LR (UK), DNV GL (Norway / Germany), ABS (USA), and NK (Japan).0°10°20°30°40°50°60°。

ver. 04-06-23PNY GEFORCE RTX™ 4070 12GB VERTO Dual Fan Edition DLSS 3NVIDIA Ada Lovelace Streaming MultiprocessorsUp to 2x performance and power efficiency 4th Generation Tensor Cores Up to 4x performance with DLSS 3 vs. brute-force rendering3rd Generation RT Cores Up to 2x ray tracing performance COLOSSAL PERFORMANCE AND SPEEDNVIDIA ® GeForce RTX™ 40 Series GPUs are beyond fast for gamers and creators. They're powered by the ultra-efficient NVIDIA Ada Lovelace architecture which delivers a quantum leap in both performance and AI-powered graphics. Experience lifelike virtual worlds with ray tracing and ultra-high FPS gaming with the lowest latency. Discover revolutionary new ways to create and unprecedented workflow acceleration.Get equipped for stellar gaming and creating with the NVIDIA ® GeForce RTX™ 4070. It’s built with the ultra-efficient NVIDIA Ada Lovelace architecture. Experience fast ray tracing, AI-accelerated performance with DLSS 3, new ways to create, and much more.The new NVIDIA ® Ada Lovelace architecture delivers a quantum leap in performance, efficiency, and AI-powered graphics. It has new Streaming Multiprocessors, 3rd generation Ray Tracing Cores, and 4th generation Tensor Cores. It’s built on a new custom TSMC 4N process, runs with blazing fast clocks, and features a large L2 cache. It enables fast ray tracing, new ways to create, and much more.PNY Technologies, Inc. 100 Jefferson Road, Parsippany, NJ 07054 | Tel 973-515-9700 | Fax 973-560-5590 | Features and specifications subject to change without notice. The PNY logo is a registered trademark of PNY Technologies, Inc. All other trademarks are the property of their respective owners. © 2023 PNY Technologies, Inc. All rights reserved. © 2023 NVIDIA Corporation. NVIDIA, the NVIDIA logo, GeForce, GeForce Experience, GeForce RTX, and G-SYNC are registered trademarks and/or trademarks of NVIDIA Corporation in the United States and other countries. All other trademarks and copyrights are the property of their respective owners.PRODUCT SPECIFICATIONS NVIDIA ® CUDA Cores 5888Clock Speed 1920 MHz Boost Speed 2475 MHz Memory Speed (Gbps) 21Memory Size 12GB GDDR6X Memory Interface 192-bit Memory Bandwidth (Gbps) 504TDP 200 W NVLink Not Supported Outputs DisplayPort 1.4 (x3), HDMI 2.1Multi-Screen 4Resolution 7680 x 4320 @120Hz (Digital)³Power Input One 8-Pin Bus Type PCI-Express 4.0 x16PRODUCT INFORMATION PNY Part Number VCG407012DFXPB1UPC Code 751492775005Card Dimensions 9.74" x 4.74" x 1.61"; Dual Slot 247.41 x 120.35 x 40.78mm; Dual Slot Box Dimensions 12.78" x 6.77" x 3.54" 325 x 172 x 90mm SYSTEM REQUIREMENTS• PCI Express-compliant motherboard with one dual width x16 graphics slot • One 8-pin supplementary power connectors • 650 W or greater system power supply²• Microsoft Windows ® 11 64-bit, Windows 10 (November 2018 or later) 64-bit, Linux 64-bit• Internet connection¹ 1 Graphics Card driver is not included in the box; GeForce Experience will download the latest GeForce driver from the Internet after install.2 Minimum is based on a PC configured with a Ryzen 9 5900X processor. Power requirements can be different depending on system configuration.3 Up to 4K 12-bit HDR at 240Hz with DP 1.4a + DSC or HDMI 2.1a + DSC. Up to 8K 12-bit HDR at 60Hz with DP 1.4a + DSC or HDMI 2.1a + DSCKEY FEATURES • Powered by NVIDIA DLSS 3, ultra-efficient Ada Lovelace arch, and full ray tracing • Dedicated Ray Tracing Cores • Dedicated Tensor Cores • NVIDIA DLSS 3• Game Ready and NVIDIA Studio Drivers • NVIDIA ® GeForce Experience™• NVIDIA Broadcast • NVIDIA G-SYNC ®• NVIDIA GPU Boost™• PCI Express ® Gen 4• Microsoft DirectX ® 12 Ultimate • Vulkan RT APIs, Vulkan 1.3, OpenGL 4.6• HDCP 2.3• DisplayPort 1.4a, up to 4K at 240Hz or 8K at 60Hz with DSC, HDR • As specified in HDMI 2.1a: up to 4K 240Hz or 8K 60Hz with DSC, Gaming VRR, HDR。

Spectrally Pure RF Photonic Source Based on a Resonant Optical Hyper-Parametric OscillatorW.Liang,D.Eliyahu,A.B.Matsko,V.S.Ilchenko,D.Seidel,and L.Maleki OEwaves Inc.,465N.Halstead Street,Suite140,Pasadena,California,91107,USAABSTRACTWe demonstrate a free running10GHz microresonator-based RF photonic hyper-parametric oscillator charac-terized with phase noise better than-60dBc/Hz at10Hz,-90dBc/Hz at100Hz,and-150dBc/Hz at10MHz. The device consumes less than25mW of optical power.A correlation between the frequency of the continuous wave laser pumping the nonlinear resonator and the generated RF frequency is confirmed.The performance of the device is compared with the performance of a standard opticalfiber based coupled opto-electronic oscillator of OEwaves.Keywords:Whispering Gallery Modes,RF Photonic Oscillator,Phase Noise,Spectrally Pure X-band Oscillator, coupled opto-electronic oscillator,opto-electronic oscillator1.INTRODUCTIONStabilized optical frequency combs are promising for generation of spectrally pure radio frequency(RF)signals. The signals are produced by demodulating the optical harmonics of the frequency combs on a fast photodiode. High degree of relative phase locking of the optical harmonics results in generation of spectrally pure RF signals. For example,a mode locked optical frequency comb was used to generate10GHz signals with phase noise at the level of-100dBc/Hz at1Hz offset and-179dBc/Hz at1MHz and higher offsets.1,2This is40dB lower than the phase noise of the best room-temperature electronic oscillators.The output power of the10GHz RF source can reach25mW when a uni-traveling carrier photodiode is illuminated with picosecond pulses from a repetition-rate-multiplied Ti:sapphire modelocked laser.3Hyper-parametric RF photonic oscillators based on high-Q Whispering Gallery Mode(WGM)microresonators are noticeable among optical frequency comb-based RF sources because of their compactness,power efficiency, and low acceleration sensitivity.4–7The phase noise of a compact WGM resonator based hyper parametric (Kerr comb)RF photonic oscillators is comparable with the noise of existing electronic oscillators,e.g.dielectric resonator oscillators(DRO).For instance,a good DRO,e.g.8GHz Hittite HMC-C200,has phase noise of-122 dBc/Hz at10kHz and-140dBc/Hz at100kHz offset.In the past we have demonstrated10GHz and35GHz Kerr comb RF photonic oscillators with phase noise of-115dBc/Hz at10kHz offset and-130dBc/Hz at100 kHz offset.8A unique advantage of the photonic oscillator is in the possibility of increasing of the generation frequency without performance degradation.Multimode microresonator-based Raman9and Brillouin10–14lasers can also be used for RF generation instead of the Kerr frequency combs.The operation of the devices is identical to the optical comb based devices–the frequency harmonics are demodulated at a fast photodiode to produce a spectrally pure RF signal at the frequency corresponding to the repetition rate of the harmonics.An important difference between the lasers and the hyper-parametric oscillator is that the phase locking of the harmonics have different phase locking mechanisms in the Raman and Brillouin lasers.The phase locked Raman laser allowed generating35GHz RF signals characterized with phase noise of-30dBc/Hz at100Hz offset and-140dBc/Hz at10MHz and higher offsets.9The best phase noise achieved with a microresonator-based Brillouin laser and reported so far(21.7GHz carrier frequency is set by the resonator host material properties)is-30dBc/Hz at100Hz offset,-90dBc/Hz at10kHz offset,-110dBc/Hz at100kHz offset,and-160dBc/Hz at100MHz and higher frequency offsets.13Send correspondence to A.B.Matsko:Andrey.Matsko@Laser Resonators, Microresonators, and Beam Control XVI, edited by Alexis V. Kudryashov,Alan H. Paxton, Vladimir S. Ilchenko, Lutz Aschke, Kunihiko Washio, Proc. of SPIEVol. 8960, 896010 · © 2014 SPIE · CCC code: 0277-786X/14/$18 · doi: 10.1117/12.2044826Figure1.Schematic of the setup of the RF photonic oscillator based on optical hyper-parametric oscillation in a MgF2 crystalline whispering gallery mode resonator(WGMR).The resonator is pumped with a semiconductor DFB laser using an evanescent prism coupler made of BK7glass.Since the free running laser linewidth(≈5MHz)is much larger as compared with the unloaded bandwidth of the resonator modes,the laser needs to be locked to the resonator mode.The locking is achieved with help of resonant stimulated Rayleigh scattering(SRS)of light in the body of the resonator.21 When the pump power exceeds certain threshold,the light exiting the resonator through another BK7prism coupler is modulated at the frequency approximately equal to the free spectral range of the resonator.The modulation corresponds to generation of the optical frequency comb(Kerr comb).Demodulating the light on a fast photodiode(PD)we generate spectrally pure radio frequency(RF)signals at frequencies corresponding to multiples of the free spectral range of the resonator.An important advantage of the RF photonic oscillators based on the Brillouin lasing is their power efficiency. The output RF power leaving the photodiode exceeds1mW without any optical or RF amplification.13The noise floor as well as the output RF power are superior over those previously reported for the microresonator-based RF photonic oscillators.It is possible to generate RF frequency signals using opticalfiber devices with resonators utilized as passive filters.Opto-electronic oscillators(OEOs)and mode locked lasers operate in this way.15–18The phase noise of a free running10GHz harmonically mode-locked semiconductor ring laser with an optical etalon(resonator)is at the level of-90dBc/Hz at10Hz offset,-100dBc/Hz at10kHz offset,and-140dBc/Hz at10MHz and higher frequency offsets.16Optical microresonators also can be used as resonant nonlinear elements infiber lasers.19,20Such a config-uration simplifies locking the system to achieve stable operation.Phase noise of the devices is not studied in detail yet.In this work we report on the development and fabrication of an RF photonic oscillator based on the Kerr frequency comb device that demonstrates phase noise order of magnitude lower as compared to the earlier ly,our oscillator has phase noise better than-60dBc/Hz at10Hz,-90dBc/Hz at 100Hz,and-150dBc/Hz at10MHz.The device consumes less than25mW of optical power.The total power consumption is determined by the thermal stabilization of the platform and is about2W.Therefore,the performance of the oscillator is superior as compared with the performance of existing compact RF photonic oscillatorsWe present the measurement results of the Kerr frequency comb oscillator and compare it with performance of OEwaves coupled opto-electronic oscillator in Section II of the paper.The origin of the phase noise limitations of the comb oscillator is investigated in Section III.In the same section we present a study of correlations between frequency of the pump laser and frequency of the RF signal.Section VI concludes the paper.2.EXPERIMENT2.1RF photonic hyper-parametric oscillatorWe created an RF photonic oscillator based on the optical frequency comb generated in a high-Q MgF2whispering gallery mode(WGM)resonator.A schematics of the oscillator setup is shown in Fig.(1).A WGM optical resonator is fabricated by mechanical polishing of a cylindrical crystalline preform.The resonator has7.1mm in diameter,0.1mm in thickness,and9.9GHz free spectral range(FSR).The intrinsic(unloaded)bandwidth of the modes is35kHz.The loaded(with two BK7prisms)bandwidth approaches300kHz.A semiconductorFigure2.(a)(b)Spectrum of the RF signal leaving the fast photodiode.The The resolution bandwidth of the measurement is 100MHz.Takingfind that the noisefloor of the signal is approximately -160dBc/Hz atdistributed feedback(DFB)laser is coupled to the resonator through the input prism and locks to a mode through the intrinsic resonant stimulated Rayleigh scattering.21This,so called self-injection locking,results in 30-40dB improvement of the laser linewidth,which is necessary to couple light from the laser to a high-Q WGM. The locking mechanism is stable even though the nonlinear process modifies the resonant response of the mode rather significantly.The threshold optical power of the frequency comb generation varies from sub mW to a few mW depending on the particular mode selected and the loaded Q.The maximum optical power sent to the resonator is less than25mW.Kerr frequency comb starts when the circulating in the mode optical power exceeds a certain threshold. Optical harmonics appear due to modulation instability of the cw background.The linewidth of the harmonics is approximately the same as the linewidth of the pump light.However,their relative frequencyfluctuations are strongly correlated.Beating of the optical comb signal leaving the resonator(Fig.2a)on a photodiode results in generation of a spectrally pure radio frequency(RF)signal(Fig.2b).We studied generation of the Kerr comb using one and two prism ually the Kerr frequency comb produced has significant energy in the nearest sidebands only(Fig.2a),RF signal generated in this regime already has very good spectral purity.We noticed that the phase noisefloor(blue curve at(Fig.3a)of the RF signal is far from the level dictated by shot noise and relative intensity noise(RIN)of the laser.This noise floor is limited by the residual phase noise of the self injection locked laser.We then generated the RF signal utilizing the comb signal transmitted through the2nd prism and the phase noisefloor was lowered to the almost -160dBc/Hz limited by shot noise(red curve at Fig.3a).It worth noting that two prism configuration was already used to reduce DC background as well as residual noise in Kerr frequency comb oscillators.22,23 We further investigated the phase noise profile of the light produced by self-injection locked DFB laser by mixing it with a narrow linewidth light produced by afiber laser(Koheras)and observed the RF beat signal on a microwave spectrum analyzer.We measured the phase noise profiles of the laser beat-note signal(10GHz frequency)at both the reflection port and the transmission port of the prism pair.The results are plotted in Fig.3b.The phase noise of the signal that involves in-transmission light is further lowed by thefiltering of the resonator,which enables us to achieve shot noise limited phase noise of the RF signal(see also Fig.2b).By selecting a different mode family of the multimode WGM resonator and changing the pump laser power,we were able to generate a Kerr frequency comb of properties different from the one aforementioned.In essence,the optical spectrum of the comb spans a much wider frequency range(Fig.4a)with RF beat signals of much lower close-in phase noise(Fig.4b).A slight change of the experimental parameters can result in rather significant modification of the performance of the system(compare red and blue curves in Fig.4b).By optimizing theFigure3.(a)Single sideband phase noise of Kerr frequency comb oscillator measured in transmission(red)and reflection (blue)ports,respectively.(b)Beat signal between the self-injection locked DFB laser and a Koheras narrow linewidth fiber laser measured with a RF spectrum analyzer.The signal of the DFB laser is retrieved from reflection(blue)and transmission ports(red),respectively.Figure4.(a)a wide range of wavelength.(b)Phase noise of the RF signal generated curves were obtained for different detuning values between the frequencies ofexperimental condition,we were able to achieve phase noise level of-60dBc/Hz at10Hz,-90dBc/Hz at100Hz, and-150dBc/Hz at10MHz.2.2Coupled opto-electronic oscillator(COEO)It is interesting to compare the phase noise of the Kerr frequency comb oscillator to that of a commercial COEO units(OEwaves Compact Opto-Electronic Oscillator)(see24,25for details)as the COEOs are among the best existing commercially available RF oscillators.The COEO units have architecture as shown in Fig.(5).A semi-conductor optical amplifier is used as the amplifying medium.The amplifier is characterized with unsaturated gain of25dB,saturation energy of1pJ,and gain recovery time of0.1ns.The average dispersion in thefiber loop is around−8ps/nm km with a nonlinearity coefficient of5W−1km−1.An electro-absorption amplitude modulator as well as an opticalfilter are utilized in these COEO units.The modulator is characterized with Vπof5V,with an insertion loss of−5dB.A portion of the light propagating in the optical cavity is coupled out and downconverted to10GHz signal.This signal isfiltered by a narrow band RFfilter,amplified and then sent back to drive the electro-optical modulator.Figure5.Schematic diagram of the coupled opto-electronic oscillator(COEO).Optical and RF loops are shown by solid black and red dashed lines,respectively.Both loops include amplifiers andfilters.The optical loop contains a semiconductor optical amplifier(SOA).The RF loop also includes an RF amplifier.A part of the light circulating in the optical loop is demodulated on a fast photodiode(PD)generating an RF signal with carrier frequency equivalent to the optical pulse repetition rate.The amplified andfiltered RF signal is fed into an electro-optical modulator(EOM).The phase of the RF signal is tuned via the phase rotatorφ.The oscillator contains two optical delay lines,one in the optical and the other in the RF feedback loops.The dispersions of the delay lines have to be optimized independently.The nonlinearity of the delay line in the optical loop should be taken into account to understand mode locking in the device, while the nonlinearity of the second delay line is generally not important because of the comparably low circulating optical power.Figure6.(a)Typical phase noise of experimentally demonstrated COEO.The peaks below100kHz in the experimental spectrum are artifacts of the measurement system.(b)Amplitude noise measured for COEO operating in mode locked (blue line)and not mode locked(red line)regimes.The noise drops significantly when the mode locked regime is achieved.An example of experimentally observed phase noise is shown in Fig.(6a).Close-in noise behavior can be explained byflicker noise of the amplifiers in the loop,as well as the thermal stabilization efficiency of thefiber. Also amplified spontaneous emission noise of the optical amplifier has to be taken into account to explain the noisefloor.To verify if the excessive phase noise comes from the conversion of the amplitude to phase noise within the COEO loop we measured the amplitude noise of the RF signal generated by the device(see Fig.6b).While the amplitude noise of the unlocked COEO is high,the mode locking reduces the noise significantly,well below the phase noise.Therefore,it is unlikely that the amplitude noise can explain the excessive phase noise.The optical pulses generated in the optical loop have an irregular shape(Fig.7a).The shape distortion comes from the slow carrier recombination time in the semiconductor optical amplifier.We expect that usage of afiber amplifier instead of the semiconductor amplifier would improve performance of the oscillator and willFigure7.Typical optical pulses(a)and associated optical was measured using an Agilent wide bandwidth oscilloscope.result in reduction of the pulse duration and pulse is a nicely shaped nearlyflat frequency comb(Fig.7b).in an imperfect the mode locking regime,the phase locking is of the RF signal generated by the comb on a fast photodiode.3.Comparing data shown at Fig.(3)and at Fig.(6a)we comb-based device is already at the same level as theresult as the size of the microresonator-based comb as compared with the size of thefiber-based device.Theand if it is possible to create a comb oscillator withTo answer this question we have performed twolaser frequency noise measurement system to detectlocked to the WGM resonator and generating a wide laser phase noise with the best phase noise of the Kerr was measured with a frequency discriminator made of of the phase noise curve for offset frequency smaller than1by the fiber MZI.The intrinsic phase noise of the laser is two curves at close-in frequency is about86dB,which is(ν0=200THz)and the FSR frequency(νRF=9.9condition,the phase noise of comb oscillator is limitedby the frequency ratio squared,ν20/ν2RF.The noise originates from the thermal noise of the WGM resonator.In the second experiment we have measured a correlation between frequencies of the pump light and the RF signal.8Since the drift of the laser frequency is primarily given by the drift of the resonator mode the laser is locked to,this kind of a measurement shows if the comb repetition frequency drift depends on the overall drift of the optical mode frequency.We can expect such a behavior from the phase noise measurement discussed above.To measure the optical frequency we utilized the heterodyne technique and used an optical local oscillator (LO)made by locking a semiconductor laser to an HCN optical transition.The measured1s stability of the optical LO was on the order of10−10,so we had to reduce the stability of our RF photonic oscillator to perform the measurement.We switched offthe direct temperature stabilization of the resonator(only the temperature of the platform was stabilized)and observed simultaneous drift of the pump laser frequency and comb repetition rate(RF frequency).RF and optical frequencies were simultaneously recorded for one day and then compared.The result of this measurement is shown in(Fig.8b).The optical and RF frequencies drifted together and the ratio of their drifts was constant and equal to the ratio of the FSR and optical frequencies.This measurement also shows that the close-in phase noise of both the laser and the resonator phase is given by the thermal drift of the resonator mode.The degree of correlation has to be studied in more details.However,even at this point,Figure8.(a)Comparison between the phase noises of an injection locked DFB laser and the generated Kerr frequencycomb RF signal.The spurs of the laser phase noise at offset frequency smaller than1kHz are from the acoustic noisepicked up by thefiber interferometer used to measure the phase noise.The difference between the phase noise valuesis about86dB at close-in frequency,which corresponds to20log(ν0/νRF)(b)Allan deviation evaluated for the carrier frequency of the cw light pumping the nonlinear WGM resonator,ν0,and for the repetition frequency of the optical comboscillator,νRF.Overlap of the Allan deviation values means that the ratio of the corresponding phase noise values of thesignals isν20/ν2RF.we can conclude that the close-in phase noise of the RF photonic oscillator is strongly influenced by the thermaldrifts of the WGM resonator.Stabilization of the resonator temperature should reduce the noise.4.CONCLUSIONWe have demonstrated a WGM-based RF photonic Kerr frequency comb oscillator with low phase noise valueapproaching phase noise value of afiber-based coupled opto-electronic oscillator.We found that the close-in phase noise of the comb oscillator depends on the frequency drifts of the nonlinear whispering gallery mode resonator.Further thermal and mechanical stabilization of the resonator will result in improvement of the RF phase noise.AcknowledgmentsThe authors acknowledge support from Defense Sciences Office of Defense Advanced Research Projects Agency under contract No.W911QX-12-C-0067as well as support from Air Force Office of Scientific Research under contract No.FA9550-12-C-0068.REFERENCES1.T.M.Fortier M.S.Kirchner,F.Quinlan,J.Taylor,J.C.Bergquist,T.Rosenband,N.Lemke,A.Ludlow,Y.Jiang,C.W.Oates,and S.A.Diddams,”Generation of ultrastable microwaves via optical frequency division,”Nature Photonics5,425-429(2011).2.F.Quinlan,T.M.Fortier,H.Jiang,A.Hati,C.Nelson,Y.Fu,J.C.Campbell,and S.A.Diddams,”Exploiting shot noise correlations in the photodetection of ultrashort optical pulse trains,”Nature Photonics 7,290-293(2013).3.T.M.Fortier,F.Quinlan,A.Hati,C.Nelson,J.A.Taylor,Y.Fu,J.Campbell,and S.A.Diddams,”Photonic microwave generation with high-power photodiodes,”Opt.Lett.38,1712-1714(2013).4.A.A.Savchenkov,A.B.Matsko,D.Strekalov,M.Mohageg,V.S.Ilchenko,and L.Maleki,”Low thresholdoptical oscillations in a whispering gallery mode CaF2resonator,”Phys.Rev.Lett.93,243905(2004).5.A.A.Savchenkov,A.B.Matsko,V.S.Ilchenko,I.Solomatine,D.Seidel,and L.Maleki,”Tunable opticalfrequency comb with a crystalline whispering gallery mode resonator,”Phys.Rev.Lett.101,093902(2008).6.A.A.Savchenkov,E.Rubiola,A.B.Matsko,V.S.Ilchenko,and L.Maleki,Phase noise of whisperinggallery photonic hyper-parametric microwave oscillators,Opt.Express16,4130-4144(2008).7.L.Maleki,V.S.Ilchenko,A.A.Savchenkov,W.Liang,D.Seidel,and A.B.Matsko,”High performance,miniature hyper-parametric microwave photonic oscillator,”Proc.2010IEEE International Frequency Con-trol Symposium,pp.558–563(2010).8.A.A.Savchenkov,D.Eliyahu,W.Liang,V.S.Ilchenko,J.Byrd,A.B.Matsko,D.Seidel,and L.Maleki,”Stabilization of a Kerr frequency comb oscillator,”Opt.Lett.38,2636-2639(2013).9.W.Liang,V.S.Ilchenko,A.A.Savchenkov,A.B.Matsko,D.Seidel,and L.Maleki.”Passively mode-lockedRaman laser,”Physical Review Letters105,art.no.143903(2010).10.J.H.Geng,S.Staines,and S.B.Jiang,”Dual-frequency Brillouinfiber laser for optical generation of tunablelow-noise radio frequency/microwave frequency,”Opt.Lett.33,1618(2008).11.I.S.Grudinin,A.B.Matsko,and L.Maleki,”Brillouin Lasing with a CaF2Whispering Gallery ModeResonator,”Phys.Rev.Lett.102,043902(2009).12.M.C.Gross,P.T.Callahan,T.R.Clark,D.Novak,R.B.Waterhouse,and M.L.Dennis,”Tunablemillimeter-wave frequency synthesis up to100GHz by dual-wavelength Brillouinfiber laser,”Opt.Express 18,13321-13330(2010).13.J.Li,H.Lee,and K.J.Vahala.”Microwave synthesizer using an on-chip Brillouin oscillator,”NatureCommunications4,art.no.2097(2013).14.B.J.Eggleton,C.G.Poulton,and R.Pant”Inducing and harnessing stimulated Brillouin scattering inphotonic integrated circuits,”Advances in Optics and Photonics5,536-587(2013).15.P.J.Delfyett,S.Gee,M.T.Choi,H.Izadpanah,W.Lee,S.Ozharar,F.Quinlan,and T.Yimaz,”Op-tical frequency combs from semiconductor lasers and applications in ultrawideband signal processing and communications,”J.Lightwave Technol.7,2701-2719(2006).16.S.Gee,F.Quinlan,S.Ozharar,and P.J.Delfyett,”Simultaneous optical comb frequency stabilization andsuper-mode noise suppression of harmonically mode-locked semiconductor ring laser using an intracavity etalon,”IEEE Photon.Technol.Lett.17,199-201(2005).17.F.Quinlan,C.Williams,S.Ozharar,S.Gee,and P.J.Delfyett,”Self-Stabilization of the optical frequenciesand the pulse repetition rate in a coupled optoelectronic oscillator,”J.Lightwave Technol.26,2571-2577 (2008).18.F.Quinlan,S.Ozharar,S.Gee,and P.J.Delfyett,”Harmonically mode-locked semiconductor-based lasersas high repetition rate ultralow noise pulse train and optical frequency comb sources,”J.Opt.A:Pure Appl.Opt.11,103001(2009).19.A.Pasquazi,L.Caspani,M.Peccianti,M.Clerici,M.Ferrera,L.Razzari,D.Duchesne,B.E.Little,S.T.Chu,D.J.Moss,and R.Morandotti,”Self-locked optical parametric oscillation in a CMOS compatible microring resonator:a route to 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RT9187B®DS9187B-03 March 2012©Copyright 2012 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation.Pin ConfigurationsApplicationsCDMA/GSM Cellular Handsets Battery-Powered EquipmentLaptop, Palmtops, Notebook Computers Hand-Held InstrumentsMini PCI & PCI-Express Cards PCMCIA & New CardsPortable Information Appliances600mA, Ultra-Low Dropout, Ultra-Fast CMOS LDO RegulatorOrdering InformationGeneral DescriptionThe RT9187B is a high-performance, 600mA LDO regulator,offering extremely high PSRR and ultra-low dropout. This chip is ideal for portable RF and wireless applications with demanding performance and space requirements. A noise reduction pin is also available for further reduction of output noise. Regulator ground current increases only slightly in dropout, further prolonging the battery life. The RT9187B also works well with low-ESR ceramic capacitors, reducing the amount of board space necessary for power applications, critical in hand-held wireless devices.The RT9187B consumes less than 0.1μA in shutdown mode and has fast turn-on time for less than 40μs. The other features include ultra-low dropout voltage, high output accuracy, current limiting protection, and high ripple rejection ratio. The RT9187B is available in the SOT-23-5package.(TOP VIEW)SOT-23-5FeaturesUltra-Low-Noise for RF ApplicationUltra-Fast Response in Line/Load Transient Quick Start-Up (Typically 40μs)<0.1μA Standby Current When Shutdown Low Dropout : 100mV at 500mAWide Operating Voltage Ranges : 2.5V to 5.5V TTL-Logic-Controlled Shutdown Input Current Limiting Protection Thermal Shutdown ProtectionOnly 2.2μF Output Capacitor Required for Stability High Power Supply Rejection RatioRoHS Compliant and Halogen FreeNote :Richtek products are :` RoHS compliant and compatible with the current require-ments of IPC/JEDEC J-STD-020.` Suitable for use in SnPb or Pb-free soldering processes.RT9187BG : Green (Halogen Free and Pb Free)04= : Product CodeDNN : Date CodeRT9187B©Copyright 2012 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation.Typical Application CircuitFunction Pin DescriptionNote : The value of R2 should be less than 80k Ω to maintain regulation.21R R 1+ V OUT = 0.8 x ( ) VoltsFunction Block DiagramENVIN OUT VRT9187BDS9187B-03 March 2012©Copyright 2012 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation.Absolute Maximum Ratings (Note 1)Supply Input Voltage -------------------------------------------------------------------------------------------------------6V EN Input Voltage ------------------------------------------------------------------------------------------------------------6VPower Dissipation, P D @ T A = 25°CSOT-23-5---------------------------------------------------------------------------------------------------------------------0.400WPackage Thermal Resistance (Note 2)SOT-23-5, θJA ----------------------------------------------------------------------------------------------------------------250°C/W Lead Temperature (Soldering, 10 sec.)--------------------------------------------------------------------------------260°C Junction T emperature ------------------------------------------------------------------------------------------------------150°CStorage T emperature Range ---------------------------------------------------------------------------------------------−65°C to 150°CESD Susceptibility (Note 3)HBM ---------------------------------------------------------------------------------------------------------------------------2kV MM -----------------------------------------------------------------------------------------------------------------------------200VRecommended Operating Conditions (Note 4)Supply Input Voltage -------------------------------------------------------------------------------------------------------2.5V to 5.5V EN Input Voltage ------------------------------------------------------------------------------------------------------------0V to 5.5VJunction T emperature Range ---------------------------------------------------------------------------------------------−40°C to 125°CAmbient T emperature Range ---------------------------------------------------------------------------------------------−40°C to 85°CElectrical Characteristics(V IN = V OUT + 1V, V EN = V IN , C IN = C OUT = 2.2μF (Ceramic), T A = 25°C, unless otherwise specified)RT9187B©Copyright 2012 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation.Note 1. Stresses beyond those listed “Absolute Maximum Ratings ” may cause permanent damage to the device. These arestress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions may affect device reliability.Note 2. θJA is measured at T A = 25°C on a low effective thermal conductivity single-layer test board per JEDEC 51-3.Note 3. Devices are ESD sensitive. Handling precaution is recommended.Note 4. The device is not guaranteed to function outside its operating conditions.Note 5. Quiescent, or ground current, is the difference between input and output currents. It is defined by I Q = I IN - I OUT under noload condition (I OUT = 0mA). The total current drawn from the supply is the sum of the load current plus the ground pin current.Note 6. Standby current is the input current drawn by a regulator when the output voltage is disabled by a shutdown signal(V EN <0.6V).Note 7. The dropout voltage is defined as V IN − V OUT , which is measured when V OUT is V OUT(NORMAL) − 100mV.Note 8. Regulation is measured at constant junction temperature by using a 2ms current pulse. Devices are tested for loadregulation in the load range from 10mA to 0.5A.RT9187BDS9187B-03 March 2012©Copyright 2012 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation.Quiescent Current vs. Temperature0100200300400500-50-25255075100125Temperature (°C)Q u i e s c e n t C u r r e n t (µA )Typical Operating Characteristics(C OUT = 2.2μF/x5R, unless otherwise specified )Quiescent Current vs. Input Voltage33.544.555.5Input Voltage (V)Q u i e s c e n t C u r r e n t (µA )Dropout Voltage vs. Load Current03060901201500.00.10.20.30.40.5Load Current (A)D r o p o u t V ol t a g e (m V )Start UpTime (25μs/Div)V IN = 3.3V I LOAD : 500mA2412V EN (V)V OUT (V)Time (100μs/Div)EN Pin Shutdown ResponseV IN = 3.3V, I LOAD : 500mA 510240V EN (V)V OUT (V)Current LimitTime (1ms/Div)O u t p u t C u r r e n t (A )V IN = 3.3V 451203RT9187B©Copyright 2012 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation.PSRRP S R R (d B )Load Transient ResponseTime (100μs/Div)V IN = 5V, I OUT = 10mA to 0.3AV OUT (50mV/Div)I OUT(200mA/Div)Line Transient ResponseTime (500μs/Div)V IN = 3.3V to 4.3V, I LOAD : 300mA3.34.310-10V IN (V)V OUT (mV)Region of Stable C OUT ESR vs. Load Current0.0010.010.11101000.10.20.30.40.5Load Current (A)R e g i o n o f S t a b l e C O U TE S R (Ω)R e g i o n o f S t a b l e C O U T E S R (Ω)RT9187BDS9187B-03 March 2012©Copyright 2012 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation.Applications InformationOutput Voltage SettingThe voltage divider resistors can have values up to 80k Ωbecause of the very high impedance and low bias current of the sense comparator. The output voltage is set according to the following equation :⎛⎞×⎜⎟⎝⎠OUT REF R1V = V 1+R2where VREF is the reference voltage with a typical value of 0.8V.Chip Enable OperationThe RT9187B goes into sleep mode when the EN pin is in a logic low condition. In this condition, the pass transistor,error amplifier, and band gap are all turned off, reducing the supply current to 1μA (max.). The EN pin can be directly tied to VIN to keep the part on.C IN and C OUT SelectionLike any low dropout regulator, the external capacitors of the RT9187B must be carefully selected for regulator stability and performance. Using a capacitor of at least 2.2μF is suitable. The input capacitor must be located at a distance of not more than 0.5 inch from the input pin of the IC. Any good quality ceramic capacitor can be used.However, a capacitor with larger value and lower ESR (Equivalent Series Resistance) is recommended since it will provide better PSRR and line transient response. The RT9187B is designed specifically to work with low ESR ceramic output capacitor for space saving and performance consideration. Using a ceramic capacitor with value at least 2.2μF and ESR larger than 10m Ω on the RT9187B output ensures stability. Nevertheless, the RT9187B can still work well with other types of output capacitors due to its wide range of stable ESR. “Typical Operating Characteristics ”shows the allowable ESR range as a function of load current for various output capacitance. Output capacitors with larger capacitance can reduce noise and improve load transient response, stability, and PSRR. The output capacitor should be located at a distance of not more than 0.5 inch from the output pin of the RT9187B.Thermal ConsiderationsFor continuous operation, do not exceed absolute maximum junction temperature. The maximum power dissipation depends on the thermal resistance of the IC package, PCB layout, rate of surrounding airflow, and difference between junction and ambient temperature. The maximum power dissipation can be calculated by the following formula :P D(MAX) = (T J(MAX) − T A ) / θJAwhere T J(MAX) is the maximum junction temperature, T A is the ambient temperature, and θJA is the junction to ambient thermal resistance.For recommended operating condition specifications, the maximum junction temperature is 125°C. The junction to ambient thermal resistance, θJA , is layout dependent. For SOT-23-5 packages, the thermal resistance, θJA , is 250°C/W on a standard JEDEC 51-3 single-layer thermal test board. The maximum power dissipation at T A = 25°C can be calculated by the following formula :P D(MAX) = (125°C − 25°C) / (250°C/W) = 0.400W for SOT-23-5 packageThe maximum power dissipation depends on the operating ambient temperature for fixed T J(MAX) and thermal resistance, θJA . The derating curve in Figure 1 allows the designer to see the effect of rising ambient temperature on the maximum power dissipation.Figure 1. Derating Curve of Maximum Power Dissipation0.000.050.100.150.200.250.300.350.400.45255075100125Ambient Temperature (°C)M a x i m u m P o w e r D i s s i p a t i o n (W )RT9187BRichtek Technology Corporation5F, No. 20, Taiyuen Street, Chupei City Hsinchu, Taiwan, R.O.C.Tel: (8863)5526789Richtek products are sold by description only. Richtek reserves the right to change the circuitry and/or specifications without notice at any time. Customers shouldobtain the latest relevant information and data sheets before placing orders and should verify that such information is current and complete. Richtek cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Richtek product. Information furnished by Richtek is believed to be accurate and reliable. However, no responsibility is assumed by Richtek or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Richtek or its subsidiaries.Outline DimensionA1HLSOT-23-5 Surface Mount Package。

英文2 ionization chamber2 pulse counting assembly4 ionization chamber4 pulse counting assemblyA batterya bomba.c.a.m.u.a.w.u.A/D converteraarraasabc neutron source abcabc weaponsabernathyiteaberrationabilityabmrabnormalabnormalabnormal conditionabnormal exposureabnormal exposure conditionabnormal operationabnormal operation transientabnormal radiationabnormal temperature riseabove criticalabove water nuclear explosion abovegroundaboveground cableabrading particlesabrasionabrasiveabrasiveabrasive blasting abrasive flap wheel abrasive particles abrasive wearabrasive wheelabscissaabsence of hang-up absolute activity absolute ageabsolute assayabsolute atomic weight absolute blackbody absolute calibration absolute counting absolute densityabsolute disintegration rate absolute electrometer absolute encoder absolute errorabsolute errorabsolute etherabsolute filterabsolute filter bank absolute filter package absolute fluxabsolute humidity absolute measurement absolute pressure absolute specific gravity absolute temperatureabsolute temperature absolute unitabsolute valueabsolute zeroabsorbabsorbabilityabsorbed doseabsorbed dose equivalent rate absorbed dose index absorbed dose rate absorbed dose rate absorbed dose rate absorbentabsorbent capacity absorberabsorberabsorber chillerabsorber element absorber rodabsorbing agent absorbing material absorbing medium absorbing power absorbing rodabsorptionabsorptionabsorption analysis absorption analysis absorption band absorption build-up factor absorption coefficient absorption coefficient absorption columnabsorption controlabsorption controlabsorption cross sectionabsorption cross sectionabsorption curveabsorption doseabsorption edgeabsorption efficiencyabsorption equivalentabsorption extractionabsorption factorabsorption factorabsorption indexabsorption lengthabsorption lengthabsorption limitabsorption lineabsorption lineabsorption mean free pathabsorption methodabsorption modelabsorption monte carlo reactor computer code absorption of beta particlesabsorption of gamma radiationabsorption of radiant energyabsorption peakabsorption probabilityabsorption ratioabsorption spectrumabsorption spectrumabsorptiveabsorptive powerabsorptivityabundanceabundanceabundance of isotopes abundance ratio abundance ratio (isotopes)acac bridgeAC generatorAC motorac voltageaccaccel decel aperture accelerated particle accelerating agent accelerating chamber accelerating electrode accelerating force accelerating period accelerating tube accelerating voltage accelerationaccelerationacceleration cavity acceleration period(motor) acceleration pressure loss acceleration voltage acceleratoraccelerator breeding accelerator dynamics accelerator focusing accelerator mass spectrometry accelerator technology accelerometeraccelerometeracceptable quality level acceptable results acceptanceacceptanceacceptance criteria acceptance criterion acceptance limit acceptance report acceptance standard acceptance testacceptance testacceptance tested(filler metals) acceptoraccessaccess areaaccess authorization for…access for inspectionaccess hatchaccess panelaccess plugaccess portaccess rampaccessibilityaccessibleaccessible-neutral accessories(filters,scoops,etc.) accessoryaccidentaccident analysisaccident analysisaccident conditionaccident conditionsaccident interlocking module accident managementaccident mitigationaccident operating conditions accident preventionaccident shutdownaccident sourceaccidental coincidenceaccidental coincidence correction accidental detonationaccidental erroraccidental exposureaccidental exposureaccidental exposureaccidental high exposure accidental lossaccidental releaseaccompanying elementaccountaccount balanceaccount totalaccountabilityaccountability tankaccountancy detection probability accounting for and control of material accounting recordsaccounting reportaccoustic emission detector accreditationaccreditedaccumulated doseaccumulated doseaccumulated doseaccumulated pressure accumulationaccumulationaccumulation effect accumulation ringaccumulatoraccumulatoraccumulatoraccumulator injection accumulator tankaccumulator tankaccuracyaccuracyaccuracy of measurement accuracy of readingaccurate x ray structure analysis acdachievement of qualityachromatachromatic lensachromaticityachromatismacidacid coveringacid etchingacid resistanceacid-proofacid-proof coatingacid-proof tileackacknowledgement(signal,alarm,etc.) aclinic lineacousticacoustic emissionacoustic frequencyacoustic heatingacoustic pressureacoustic strain gauge(containment instrumentation) acoustic velocityacoustic waveacousticalacoustical adj.acousticsacpracquisition rateacsactie energyactinic raysactinideactinide elementactinide elementsactinide lanthanide separationactinide metallideactinide seriesactinidesactiniumactinium aactinium bactinium cactinium emanationactinium familyactinium groupactinium kactinium leadactinium seriesactinium xactino uraniumactino uranium series actinodermatitis actinogenicsactinoid contraction actinologyactinometeractinonactionaction at a distanceaction planaction variableactivable traceractivateactivated adsorption activated carbonactivated charcoalactivated charcoal filter activated charcoal filter bank activated charcoal filter package activated complexactivated moleculeactivated nucleusactivated sludgeactivated wateractivated wateractivating agentactivationactivationactivation analysisactivation cross section activation curveactivation detectoractivation detectoractivation energyactivation energyactivation foilactivation methodactivation method of cross section determination activation productsactivatoractiveactiveactive areaactive carbonactive carbon filteractive centeractive componentactive componentactive core heightactive depositactive element groupactive failureactive fall outactive fuel lengthactive height(fuel)active hydrogenactive latticeactive laundryactive lengthactive loopactive loopactive massactive neutron methodactive poisonactive poweractive poweractive poweractive power meteractive solventactive surface agentactive valenceactive volumeactive well coincidence counter active zoneactivited carbonactivityactivityactivityactivity affecting qualityactivity build upactivity coefficientactivity concentrationactivity concentrationactivity concentrationactivity curveactivity curveactivity decayactivity levelactivity levelactivity mass formulaactivity meteractivity meter with automatic changer activity rangeactivity supervisoractivity unitactualactual capacity(compressor)actual ground zeroactual routine inspection effortactual yieldactuateactuate v.actuating variableactuationactuatoractuator armactuator manufactureracuacute effectacute exposureacute exposureacute radiation injuryacute radiation sicknessacute radiation syndromead hoc inspectionadamantineadaptatioradapter sleeveadaptive controladaptoradaptor lugadaptor plate(fuel assembly to nozzle)adcadderaddition or deletion of variables(welding procedure qualification) additional contactsadditional HP governing valveadditional lightingadditional loadadditional power sourceadditional workadditiveaddressadherenceadhesionadhesiveadhesive adj.adhesive forceadhesive poweradhesive tapeadhesivenessadhesivesadhesivityadiabaticadiabatic changeadiabatic compression adiabatic containment adiabatic curveadiabatic expansionadiabatic heatingadiabatic invarianceadiabatic invariantadiabatic lineadiabatic nuclear demagnetization adiabatic potentialadiabatic potential curve adiabatic principleadiabatic processadiabatic trapadionadjacent elementadjoint fluxadjoint fluxadjoint functionadjoint of the neutron flux densityadjust v.adjustableadjustable blade propelleradjustable pliersadjustable wrenchadjustingadjusting bolt bearingadjusting ring set screwadjusting screwadjustmentadjustment deviceadjustment moduleadjustment pelletadmadministration buildingadministration building and emergency center ventilation system administration building and emergency center water supply and drainage system administrative lockoutadministrative manageradmissible erroradmission pressureadmixtureadoption by equivalentadpadpsadsadsorbadsorbateadsorbentadsorptionadsorption capacityadsorption chromatographyadsorption coprecipitationadsorption method of separation adsorption potentialadsorption poweradsorption probabilityadsorption stageaduadvanced epithermal thorium reactor advanced fuel assemblyadvanced gas cooled reactoradvanced pressure tube reactor advanced pressurized water reactor advanced reactivity measurement facility advanced reactor technology advanced stellaratoradvanced test reactoradvanced test reactor critical experiment advanced thermal reactoradvanced very high resolution radiometer advantage factoradvantage factoraeaecmaedsaegaeolotropicaerationaerialaerial cableaerial radiological measuring system aerial viewaerodynamic behavioraerodynamic diameteraerogelaerometeraerosolaerosolaerosolaerosol filteraerosol monitoraerosol sampleraerosol sampling aerospace systems test reactor aesaetrafaffinityaffinity labellingAFI test (filters)afsafter cutafter effectafter filter(or post-filter) after heatafter powerafter pulseafter settlerafter treatment aftercoolingafterglowafterglowafter-heatafter-heatafterloading source afterloading technique afterloading unitafter-powerafter-power， residual heat power afterpulseafterset insertaftershockAG 5aluminum-zinc alloyageage determinationage diffusion approximationage diffusion kernelage distributionage equationage equation without capture age hardeningage hardeningage of cosmic ray irradiation age peaking factorage theoryage v.aged fission productaged uraniumagentagglomeratedagglomerated (powder) agglomerated fluxaggregateaggregate recoilaggregate recoilaggregationaggressiveaggressive atmosphere aggressive mediumaggressive wateragingagingagitateagitationagitatoragragreementagzahfahrair adj.air bathair bindingair blastair blast breakerair bleed valveair breakerair bubbleair burstair carbon arc gougingair change rateair change rateair compressorair conditioningair conduitair contaminationair contamination indicatorair contamination meterair contamination meterair contamination monitorair coolantair cooledair cooled graphite moderated reactorair cooled oil vapor diffusion pump air cooled reactorair coolerair coolerair cooler duct (electric motor)air coolingair coolingair courseair curtainair cylinderair delivery pipeair doseair dryerair ductair eductorair elutriationair entrainmentair equivalentair equivalentair equivalent ionization chamber air equivalent materialair equivalent materialair exhaustair filterair filterair filter and absorber unitair filter unitair flow baffleair flow rateair gamma surveyair gapair gapair gasair gaugeair handling unitair heaterair hoseair inletair intakeair intakeair ionizationair ionization chamberair ionizing electrodeair liftair lift extractorair lift mixer settlerair liquefierair lockair lockair lockedair magnetic breakerair monitorair monitoringair operated disk cutterair operated jawsair outletair ovenair pocketair pollutionair pressureair pressure amplifierair pumpair purifierair radiationair radiation monitor(gas or air-particulate monitors) air recirculation fanair regulatorair removalair renewalair renewal rateair samplerair samplerair samplingair sampling deviceair sampling deviceair sampling equipmentair sampling techniqueair self-cooling typeair setair set pressure test(for relief valves) air showerair specific gravityair speedair submerasion doseair supplyair supply fanair supply supportair supply terminalair thermometerair tightair to push downair to push upair transportair valveair velocityair ventair wall ionization chamberair washerair zeroair/bead mixtureairblastairblast damageairblast decayairblast induced accelerationairborne contaminantsairborne contaminationairborne debrisairborne dustairborne particulate controlairborne particulate sampleairborne particulatesairborne particulatesairborne plutoniumairborne radioactive prospectingairborne radioactivityairborne radioactivityair-break circuit breakerair-bubbler type level measurementair-bubbler type specific gravity measurement air-cooled condenserair-cooled transformeraircraft crashaircraft reactor experimentaircraft warning lightsair-entraining agent(concrete)air-entraining vortexairing circuitair-line assemblyair-operated adj.air-operated valveairox processairplane reactorairshockairtightairtight door airtightnessair-to-air coolerair-to-close valveair-to-open on-off valve air-to-open valveair-to-water cooleralalabamine alabamium alamogordo bomb alapalaraalara principlealarmalarmalarm annunciator alarm boxalarm circuitalarm dosimeter alarm lampalarm limitalarm processing alarm setalarm signalalarm windowalarm windowalarm(output) module alarmedalbedoalbedoalcalialchemyalcoholalcohol lampalcohol thermometer alcoholic extract alcoholometer aldanite aldebaraniumalfven velocity alfven wavealfven wave instability alialigningaligning pin alignmentalignment hole alignment pinaliquotalkalialkali earth metal alkali liquoralkali metalalkali proofalkali resistance alkali resisting alkalimeteralkaline accumulator alkaline battery alkaline battery alkaline cleaning alkaline liquor alkaline metalalkaline solutionalkaline storage batteryalkalinityall metalall time recordall volatile treatmentall volatile treatmentAllen screwalligatoringallobarsallomerismallomorphismallotropeallotropic modificationallotropic transformation allotropyallowableallowable errorallowable loadallowable stressallowanceallowance for fabrication tolerances allowed bandallowed beta decayalloyalloy steelalloy steelalloyed steelalluvial depositall-welded frameall-weld-metal tension(or tensile)test almen intensityalmen stripalphaalpha absorptionalpha activityalpha bearing wastealpha beta standard sourcealpha bombardmentalpha contamination indicator alpha counteralpha decayalpha decayalpha decay energyalpha disintegrationalpha emissionalpha emissionalpha emitteralpha emitteralpha emitting foilalpha hand contamination monitor alpha heatingalpha meteralpha neutron reactionalpha particlealpha particle binding energy alpha particle dosimetryalpha particle modelalpha particle model of nucleus alpha phasealpha plutoniumalpha proton reactionalpha pulse counting assembly alpha pulse height analysis alpha radiationalpha radiatoralpha radioactivealpha radioactive nucleusalpha radioactivityalpha ratioalpha ratioalpha ray emitteralpha ray shieldalpha ray spectrometeralpha ray spectrumalpha raysalpha raysalpha sourcealpha spectrometryalpha spectroscopyalpha spectrumalpha uraniumalphanumeric code alphanumeric keyboardalpha-phase producing(metallurgy) alphatopicalphatronalterationalternate energy source alternate energy sources alternate systemalternatingalternating currentalternating currentalternating current bridge alternating current motor alternating current voltage alternating fieldalternating gradient focusingalternating gradient focusing accelerator alternating gradient focusing principle alternating gradient synchrotron alternating slidingalternating stressalternationalternative energy sourcesalternatoraltitude curvealtitude effectaluminaalumina cementaluminium alloyaluminium base alloyaluminium foilaluminium nitratealuminium oxidealuminothermic process aluminothermyaluminous cementaluminous cementaluminumaluminum boridealuminum canaluminum jacketalundumalvarez type accelerator cavityamamalgamambientambient conditionsambient does rateambient lightingambient temperatureambipolar diffusionAmerican Concrete InstituteAmerican Institute of Steel Construction American National Standards Institute American Nuclear SocietyAmerican Society for Testing and Material American Society of Civil Engineers American Society of Mechanical Engineers American standard pipe thread plug americiumamericium beryllium neutron source amine extractionammeterAmmeterammeterammoniaammonia gasammonia waterammonium diuranateammonium diuranateammonium diuranate process ammonium uranyl tricarbonate amorphismamorphousamorphous carbonamorphous substanceamountampacityampangabeiteamperageampereampere hourampere meterampholyteampholytoidamphoteric colloid amphoteric compound amphoteric electrolyte amphoteric ionamphoteric metalamplfier relayamplificationamplification channel amplification constant amplification factoramplified spontaneous emission amplifieramplifieramplifying valveamplitude analyzer amplitude analyzing assembly amplitude discriminator ampouleampullaamsanabatic wind fall outanaloganalog channelanalog channelanalog controlleranalog diagramanalog digital converter analog feedback control analog inputanalog instrumentationanalog measurement analog outputanalog relayanalog signalanalog signalsanalog to digital converter analog variableanalog/digital converter analogousanalogue linkanalyseranalysisanalysis lineanalysis(of data)analyticanalyticalanalytical balance analytical chemistry analytical equipment analyzeranalyzing magnet anchoranchor baranchor boltanchor boltanchor channelanchor coneanchor drillinganchor plateanchor pointanchor ring(reactor vessel) anchor rodanchoringanchoring pointandersoniteaneroid barometeranggstromangleangleangleangle beam examinationangle beam probeangle beam ultrasonic examinationangle check valveangle control valveangle gear driveangle ironangle jointangle of emissionangle of frictionangle of frictionangle of incidenceangle of reflectionangle of refractionangle of scatteringangle of the electron gun(electron beam welding) angle of torsionangle patternangle poleangle stragglingangle styleangle towerangle valveanglesobaryteangstromangstrom unitangularangular accelerationangular adjustmentangular coordinatesangular correlationangular dependence of scatteringangular displacementangular displacement transducerangular distributionangular frequencyangular kinetic energyangular magnificationangular momentumangular momentumangular momentum conservation lawangular momentum quantum numberangular momentum transferangular monentum conservation lawangular quantum numberangular resolutionangular velocityanhydrideanhydrousanhydrous etheranhydrous hydrochlorination of zirconium bearing fuel anhydrous hydrofluoric acidanimal blackanimal charcoalanionanion bedanion bed demineralizeranion bed ion exchangeranion exchange resinanion exchange resinanion exchangeranion exchangeranion resinanion vacanciesanisotopic element anisotropicanisotropic liquid anisotropismanisotropyanisotropy factorannealedannealingannealingannealing passannealing temperature annexannihilationannihilation gamma quantum annihilation photon annihilation radiation annualannual dose equivalent limit annual limit on intake annual throughput annualized capital cost annualized energy cost annular core pulse reactor annular counterannular lightingannulusannulus(containment) annunciatedannunciatorannunciator boardannunciator lightannunciator panelanodeanode batteryanode characteristicanode circuitanode circuit efficiencyanode dropanode effectanode loadanode loopanode raysanode resistanceanode scrapanode supplyanode voltage dropanodic reactionanodisinganodizinganolyteanomalousanomalous absorption anomalous atomic scattering method anomalous diffusionanomalous magnetic moment anomalous scatteringanomalous transmission anomalous valenceanomalyanthraceneanthraciteanthraxoliteanti baryonanti carrieranti compton gamma ray spectrometeranti electronanti explosion valveanti seismic siteanti-backlash(gears)antibirdantibonding orbitalanticatalystanticatalyzeranticathodeantichatteranticipatedanticipated operational occurrences anticipated transient without scram(ATWS) anticlockwiseanticoagulantanticoagulating actionanticoincidenceanticoincidenceanticoincidence circuitanticoincidence counteranticoincidence methodanticoincidence selectoranticoincidence selector unitanti-condensation heater(reactor coolant pump) anticontamination clothinganticorrosiveanticorrosive paintantidiffusion gridantidustantiferromagnetism antifoam reagentanti-foaming agent antifouling paint antifreezeantifreezeantifriction bearinganti-frieezing agent(concrete) antihyperonantileptonantimatterantimesonantimonyantineutrinoantineutronantinucleonanti-oil whip(pump) antioxidantantioxygenantiparallelantiparallel spin antiparticleanti-popout tube antiprotonantiproton beam antiprotonic atomanti-reverseanti-reverse deviceanti-reverse system antirotation deviceanti-rotation device antirotation luganti-rust agentanti-rust paintanti-seismic plateanti-seizer lubricant antisepsisantisepticantishadowinganti-simmerantisimmer pressure relief valve antisimmer(valve) antisymmetryantivibrationanti-vibration baranti-vibration baranti-vibration bar antivibration bar attachment anti-vibration spacer baranti-whip deviceanti-whip deviceanvilaoaortographyapdmsaperiodicaperiodicityapertureaperture cardaperture diaphragmapexapex processaphaapparatusapparatusapparent lifetimeapparent powerapparent powerappearance potentialappendageappendage sensorappendixapplicabilityapplicationapplicationapplication of new lead seal application of radioisotopes and radiation application packageapplication programapplicatorapplied nuclear physicochemistry applied nuclear physicsapplied nuclear spectroscopy approachapproach to criticalityapproach to criticalityapproach(cooling tower,condenser) approvalapprovalapproved packingapproximate solutionapproximate valueapproximationapproximation calculusaprdaprmaptrapuaqua destillataaqua regiaaquarium reactoraqueousaqueous ammoniaaqueous emulsionaqueous homogeneous reactor aqueous reprocessing aqueous solutionaqueous vapouraquiferarbitraryarborarcarc blowarc chutearc dischargearc energyarc furnacearc initiationarc meltingarc strike(welding)arc trajectory(missile)archarch damarchitectural drawing architectural line weights arcing contactarc-lampardometerareareaarea containing removable ceiling or wall panels area densityarea drainarea monitorarea monitorarea monitoringarea radiation monitorarea radiation monitoring systemarea radiation monitoring systemarea supervisorarea under the notch(impact test)areal velocityarea-weighted averagingareometerareopycnometerargargillaceousargmargonargon hoseargon laserargon methodargonaut type research reactorargonne advanced research reactorargonne boiling water reactorargumentaridariearithmetic meanarithmetic meanarmarmarm rotationarmaturearmorarmorarmored cable armoring wirearmourarmourarmsaromatic nucleus aromatic ringaround-the-clock arrangement arrangement arrangement drawing arrangement of runs arrayarrayarrayarrisarsenicarsenious acidartarticlearticulated arm articulated camera mount artificail radionuclide artificialartificial diamond artificial disintegration artificial element artificial energy source artificial graphite artificial illuminationartificial intelligenceartificial lightingartificial loadartificial neutronartificial nuclear disintegrationartificial nuclear transformation artificial radioactiveartificial radioactive isotopeartificial radioactivityartificial radioactivityartificial radionuclideartificial transformation of element artificial ventilationasas builtas isas low as practicableas low as reasonable achievable(ALARA) as low as reasonably achievable asbestosasbestos cementasbestos cement sleeveasbestos paperasbestos threadasbestusas-built dimensionas-built drawingas-built(drawings)as-castas-coated roughnessascsas-deposited claddingase。