Optimization And Implementation Of The Scheme For The Generation Of High Speed And High Stability Time-wavelength-interleaved Optical Sampling Clock

With the development of photonic technology, high speed highprecision photonic analog-digital conversion has become a research focus.Photonics approaches are implemented to break through the “bottleneck” ofelectrical analog-to-digital conversion (ADC). Time-wavelength-interleavedoptical ADC is one of the most typical and realizable schemes, where theinput RF signal is modulated onto the time-wavelength-interleaved opticalsampling clock and sampled by an electro-optic modulator. With the help ofwavelength demultiplexing technology, the electrical quantization and dataprocessing are implemented. The quality of optical sampling clock is thefundamental limitation of the OADC’s performance. The amplitudefluctuation, timing jitter, pulse width and stability of optical sampling clockdirectly affect the performance of a time-wavelength-interleaved opticalADC. Thus, the generation of high speed high stability optical samplingclock is the key point.This thesis mainly studies the scheme for the generation of high speedand high stability time-wavelength-interleaved optical sampling clock whichimplements pulse repetition frequency multiplication technology such asWDM and OTDM. The main tasks include:1. The factors affecting the quality of time-wavelength-interleaved opticalsampling clock are analyzed, especially the effect of laser amplitudefluctuation and its variation of power spectral distribution. The amplitudejitter caused by the laser is modeled, and stability of spectrum slicing ismeasured experimentally. A periodic correction on the data processing is proposed to mitigating the effect of laser amplitude jitter.2. Theoretical analysis is carried out on pulse repetition frequencymultiplier based on OTDM. A novel method, polarization maintainingstructure, is proposed, which reduces the polarization sensitivity andimproves the environmental stability. The effect of22coupler splittingratio on the optical sampling pulse amplitude fluctuation is also studied.The approaches to precision length measurement and fabrication ofoptical fiber delay line are optimized. A16x OTDM pulse repetitionfrequency multiplier is fabricated.3. Two schemes of the repetition frequency multiplication module based onWDM, the reflective scheme and the polarization-controlled scheme, arecompared theoretically and experimentally. The reflective scheme with8channels is finally adapted and a128x pulse repetition frequencymultiplier is implemented. Thus a4.67GHz stable optical sampling clockis generated.