Fiber Optic Communications
Review Guideline
This guideline is aimed to provide a list of concepts covered in this course. It is advised that students should obtain a thorough understanding of the concepts, and test your understanding by answering related questions and homework problems.
Chapter 1-4
●Optical Fiber Basics
⏹Critical angle
⏹Acceptance angle
⏹NA
⏹Causes for transmission attenuation
⏹V-number calculation
⏹Estimation of mode numbers
⏹Bandwidth & bit rate
●Measurement
⏹dB and dBm
●Dispersion
⏹Intermodal
⏹Intramodal
◆Chromatic D(λ)
◆Waveguide
◆PMD
⏹Dispersion compensation fiber
⏹Dispersion->Pulse spread -> Bandwidth
●Three wavelengths:
⏹Unbounded wavelength λ=v/f
⏹Guided wavelength λg=λ/[1-(fc/f)2]1/2
⏹Cutoff wavelength λc=v/fc
●Phase and group velocity
●Modes and power distributions
⏹LP Modes
⏹Mode classification
Chapter 5-6
⏹Single mode fiber basics
⏹MFD
⏹Cutoff wavelength
⏹Waveguide dispersion and dispersion flattening
⏹Loss(causes etc.)
Chapter 7-8
⏹Four classical preform fabrication methods
⏹Intrinsic and extrinsic losses
⏹Connection loss
⏹Power budget (calculation)
⏹Rise-time budget and bandwidth check
Chapter 9-11
●Transmitter module
⏹Light source
⏹Coupling optics
⏹Driving electronics
●LED basic properties
⏹P-N junction
⏹Internal quantum efficiency
⏹Radiative/nonradiative recombination
⏹Lambertian source
⏹Spontaneous emission
⏹Rise/fall time
⏹SLED v.s. ELED
●LD basic properties
⏹Structure
◆Waveguide gain medium
◆mode
⏹Optical characteristics
◆Internal quantum efficiency
◆External quantum efficiency
◆E-O efficiency
◆Slope efficiency
◆Spectral linewidth
◆Wavelength v.s. temperature
◆Wavelength v.s. driving current
◆Threshold Current
●VCSEL basic properties
⏹Structure
⏹Advantages
⏹Optical characteristics
●DFB characteristics
⏹structure
⏹spectral linewidth
●Coupling optics
⏹Direct coupling
⏹Lens coupling
●Driving electronics
●Data conversion
⏹Non-return-to-zero code
⏹Return-to-zero code
●Modulators
⏹Mach-Zehnder
⏹Electroabsorptive
◆Monolithic
◆Low op voltage
●Direct modulation
⏹Delay time
⏹Recombination time
⏹Chirp
●Noise
⏹Phase fluctuations
⏹Intensity fluctuations
Receiver
●Receiver module
⏹Photodiode
⏹Coupling optics
⏹Preamp
⏹Quantizer
⏹Filter
⏹Amp/limiter
⏹Decision circuit
⏹Clock recovery
●Photodiode
⏹Silicon and InGaAs PIN
◆High responsivity
◆Wide Bandwidth
⏹APD
◆High sensitivity M~20
◆High reverse bias 20V ●Common characteristics
