基于延迟线干涉仪差分相移键控解调器研究

硕士学位论文基于延迟线干涉仪差分相移键控解调器研究RESEARCH ON DIFFERENTIAL PHASE-SHIFT KEYING DEMODULATOR BASED ONDELAY-INTERFEROMETER姜晋伟哈尔滨工业大学2011年06月国内图书分类号：T N929.13 学校代码：10213 国际图书分类号：621.391.6 密级：公开工学硕士学位论文基于延迟线干涉仪差分相移键控解调器研究硕士研究生：姜晋伟导 师：谭立英教授申请学位：工学硕士学科：物理电子学所在单位：光电子信息科学与技术答辩日期：2011年06月授予学位单位：哈尔滨工业大学Classified Index: TN929.13U.D.C: 621.391.6Dissertation for the Master Degree in EngineeringRESEARCH ON DIFFERENTIAL PHASE-SHIFT KEYING DEMODULATOR BASED ON DELAY-INTERFEROMETERCandidate: Jiang JinweiSupervisor: Prof. Tan LiyingAcademic Degree Applied for: Master of Engineering Speciality: Physical ElectronicsAffiliation: Dept. of Optoelectronic Information Science & TechnologyDate of Defence: June, 2011Degree-Conferring-Institution: Harbin Institute of Technology摘 要采用激光为信息载波建立卫星之间的激光通信链路，是解决目前微波通信系统传输速率和传输容量瓶颈问题的最佳解决方案，并且由于激光通信星载光终端体积小、通信链路保密性强等优点，促使各航天大国如美国、日本、德国、法国等国家相继开展卫星激光通信技术的研究，已经相继实现了星间链路、星地链路的科学实验，并积极推进其商用化。

差分相移键控（DPSK）调制/解调通信方案已经成功应用于地面光纤通信系统中，并且已经走向商用化。

与强度调制/直接探测（IM/DD）相比，在使用平衡接收的条件下，相同的误码率对光信噪比（OSNR）的要求降低了3dB，即探测灵敏度提高了3dB；与相干探测系统相比，有着与之相媲美的高灵敏度探测能力、接收机结构相对简单容易实现、采用密集波分复用技术（DWDM）可进一步增加传输容量等优点，故DPSK调制/自差探测通信体制成为卫星激光通信高速大容量传输最具发展潜力的方案之一。

在DPSK调制信号中，是利用前后相邻码元的相对载波相位值来承载信息的，需要光解调器将前后比特的相位差信息转换成振幅信息，再进行直接探测，因此DPSK信号的解调技术是DPSK格式通信系统关键技术之一，一般的解调方法是采用1比特延迟线干涉仪。

以往，这种1比特延迟的干涉仪设计都是基于全光纤或者平面波导Mach-Zehnder干涉仪来实现的，这两种设计最主要的问题都是对温度变化极为敏感，输出不稳定。

本文提出了两种温度稳定性较好的延迟线干涉仪解调器设计方案，完成的主要研究工作包括：介绍了DPSK信号调制解调的原理及信号的探测，并对其进行统一的数学分析。

提出双芯光纤型延迟线Mach-Zehnder干涉仪解调器设计方案，并对其温度特性进行了理论分析；提出了一种有加热设计的空间延迟线Michelson延迟干涉仪解调器设计方案，对无源器件工作性能参数进行了理论分析，实际研制出了该解调器，并对其性能参数进行实验测试和标定。

结果表明其主要参数与市场同类器件相比具有一定优势；搭建了一套Back-to-Back DPSK调制/自差探测光纤通信系统，并将所研制的解调器应用于该系统中，完成了40Gbps的高速解调速率。

解调后的OSNR眼图与国外同类产品相比，具有相媲美的优势。

本文的研究对DPSK调制/自差探测体制的信号解调有着极高的应用价值，并对地面光纤DPSK通信系统信号解调也极具实用化前景。

关键词：卫星光通信；差分相移键控；Michelson干涉仪；双芯光纤Mach-Zehnder 干涉仪；眼图AbstractLaser communication links between satellites, which adopts laser as the information carrier wave, is a promising solution for the increasing requirements of higher data rate and capacity as an alternative to conventional microwave. Satellite optical terminals possesses the advantages of less volume and better security. Hence laser communication technology is an attractive method to establish satellite links. Since last century 60th the satellite laser communication has been researched in countries, including America, Japan, Germany, France and so on. Space experiments have been performed for intersatellite and satellite-to-ground link. And these countries are preparing to promote this technology to commercialization.Optical communication scheme based on differential Phase-Shift Keying（DPSK）modulation/demodulation technology has already commercially applied to ground fiber communication systems. Comparing with intensity modulation/direct detection (IM/DD), for the same desired BER the required optical signal-to-noise ratio (OSNR) would be 3dB less, which means the receiver sensitivity increasing 3dB more. DPSK system has high sensitivity, which can compare with coherent detection, relatively simple configurations and especially large channel capacity by adopting dense wavelength division multiplexing technology (DWDM). Therefore, DPSK is one of the most promising ways to approach high speed and large capacity satellite laser communication.The DPSK method is achieved by comparing the phase two sequential bits, which needs to be transferred into intensity information through the demodulator before direct detecting. The DPSK demodulation technology is one of the critical technologies for DPSK communication systems. Prior typical demodulator method is 1bit delay interferometer based on all fiber or plane waveguide technologies, which have some disadvantages including temperature sensitivity and unstable output characteristics. In this paper two kinds of temperature-stability delay interferometer are proposed, and major work includes:First the principle of DPSK demodulator is introduced and mathematical analysis is also reviewed.The demodulator method of an double-core fiber Mach-Zehnder interferometer is proposed, whose temperature characteristic is studied theoretically.The demodulator method of an Michelson interferometer based on space delay line is proposed. The theoretical analysis of related parameter is given, and the demodulator is developed. The characteristic of this demodulator is exhibited according to the experimental data. Results show that this kind of demodulator owns outstanding advantages comparing to the existent equipments.A set of back-to-back DPSK modulate/self-homodying system, in which the proposed demodulator is applied, has been conducted with demodulating rate of 40Gbps. The eye graph shows comparative advantages with abroad experiments.The subject studies in this paper can benefit the DPSK modulate/self-homodying system, and would be helpful to the ground fiber DPSK communications.Keywords:inter-satellite optical communication, DPSK, Michelson interferometer, twincore fiber Mach-Zehnder interferometer, eye diagram目录摘 要 (I)Abstract (III)第1章 绪 论 (1)1.1 课题背景 (1)1.2 课题的目的和意义 (3)1.3 国内外研究状况及进展 (3)1.3.1 国外卫星相干光通信技术研究现状 (4)1.3.2 国内卫星相干光通信技术研究现状 (7)1.3.3 DPSK延迟线解调器研究现状及分析 (8)1.4 论文结构及主要内容 (11)第2章 差分相移键控信号调制/解调理论分析 (12)2.1 引言 (12)2.2 DPSK调制原理分析 (12)2.3 DPSK信号解调与检测分析 (18)2.4 本章小结 (20)第3章 双芯光纤延迟线Mach-Zehnder干涉仪解调器设计与分析 (21)3.1 引言 (21)3.2 双芯光纤延迟线Mach-Zehnder干涉仪解调器设计 (21)3.3 双芯光纤延迟线Mach-Zehnder干涉仪温度特性分析 (22)3.3.1 温度对双芯光纤延迟线Mach-Zehnder干涉仪延迟长度影响分析 (22)3.3.2 温度对双芯光纤延迟线Mach-Zehnder干涉仪信号相位影响分析 (26)3.4 本章小结 (26)第4章空间延迟线Michelson干涉仪解调器设计与分析 (27)4.1 引言 (27)4.2 空间延迟线Michelson干涉仪解调器设计 (27)4.2.1 空间延迟线Michelson干涉仪解调器设计方案 (27)4.2.2 空间延迟线Michelson干涉仪解调器工作机理分析 (28)4.3 空间延迟线Michelson干涉仪解调器参数分析 (30)4.3.1 插入损耗分析 (31)4.3.2 回波损耗分析 (31)4.3.3 隔离度分析 (31)4.3.4 自由光谱范围分析 (32)4.3.5 偏振相关损耗分析 (35)4.3.6 频率漂移分析 (36)4.3.7 延迟线Michelson干涉仪解调器设计方案优化 (38)4.4 本章小结 (39)第5章空间延迟线Michelson干涉仪解调器研制与测试分析 (40)5.1 空间延迟线Michelson干涉仪解调器研制与调试 (40)5.2 空间延迟线Michelson干涉仪解调器性能参数动态测试与分析 (42)5.2.1 插入损耗测定及结果分析 (44)5.2.2 回波损耗测定 (45)5.2.3 隔离度测定及结果分析 (45)5.2.4 自由光谱范围温变特性测定及分析 (45)5.2.5 频率漂移测定及结果分析 (46)5.2.6 偏振相关损耗测定 (47)5.3 Back-to-Back DPSK系统高速解调实验 (48)5.3.1 Back-to-Back DPSK系统高速解调实验方案 (48)5.3.2 Back-to-Back DPSK系统高速解调实验结果分析 (49)5.4 本章小结 (51)结 论 (52)附 录 (53)参考文献 (55)攻读学位期间发表的学术论文 (61)哈尔滨工业大学硕士学位论文原创性声明..................................错误！未定义书签。