High Speed Digital Signal Measurement With Electronic-Optical Sampling

The optical sampling technique of high speed digital signal using ultra-shortoptical pulse is a key technique in modern information processing, opticalperformance monitoring in the optical network and high speed optical signalmeasurement. The thesis makes investigations on the applications of optical samplingtechnology in high speed photonic analog to digital conversion and opticalperformance monitoring in optical network. Moreover, the photonic analog to digitalconversion based on time-interleave technology and asynchronous optical samplingexperiment were set up in the thesis, and corresponding experiments, includingresearches on photonic analog to digital conversion and asynchronous histogramoptical sampling experiments were made.This thesis presents a method to realize photonic analog to digital conversionbased on time-interleave, and accomplished the optical sampling experiments of4.88GHz and 3.7GHz sine microwave signal using optical pulse with a repetitionfrequency of 1.25GHz and pulse width of 7ps were studied, , which gained aconverting precision of 6 bits. The main error sources of optical sampling wereanalyzed and the influences of sampling pulse's width, time jitter and aptitude jitteron the analog to digital conversion precision were simulatedThe thesis expatiates the principles of evaluating the bit rate error by histogram,meanwhile make experiments on the asynchronous sampling principle using pulseseries of sub-pocosecond in width from a passive mode lock laser. As a result,asynchronous histogram of 2.5GHz microwave signal of sine pattern, 2.5GHz PseudoRandom Bit Sequence (PRBS) and 10GHz optical asynchronous sampling wereobtained. The software synchronization method which can be used on recovery of eyediagram of asynchronous sampling data was analyzed, and the result of simulationshows that asynchronous histogram method and the software synchronization methodwere both transparent to the code pattern and bit rate. The eye diagram of 2.5GHzsine microwave signal was successfully recovered from asynchronous sampling databy the technology.The researches on the passive mode lock fiber laser based on nonlinearpolarization rotation effect are also involved in the thesis. Pulse series with repeatingfrequency of 5MHz and pulse width of less than 1ps were attained, and the shape ofthe pulse, the electric spectrum and optical spectrum were measured and analyzed.