At present, the ultra-fast, ultra-long-distance and large-capacity optical fiber communication technology is the polish hot and the main direction of international communications research. For achieving ultra-high speed optical time-division multiplexing transmission, optical soliton transmission and high-speed optical switch, the generation of high repetition rate, ultra-short optical pulse is one of the key technologies. InGaAsP / InP multi-quantum wells(MQW) mode-locked semiconductor laser is a new type of light resource, which produces ultra-short coherent light pulses with a narrow pulse width, small frequency chirp , high repetition rate, the output wavelength of 1.55μm, wide wavelength tunable range, simple structure, easy-to - precise control of output wavelength, good stability and so on. The lasers in the topics introduces MQW technology, active-passive hybrid mode-locking mechanism, what's more in the experiment we has successfully produced a pulse width of 2.9ps, time-bandwidth product of 0.43 (very close to the transformation of Gaussian wave limit) .So is an ideal source for optical time-division multiplexing (OTDM) system.In this paper, the first part makes a brief presentation about OTDM system and the mode-locked semiconductor and in the comparison presents mode-locked multi-quantum-well semiconductor lasers advantages; Secondly, basic theoretical research about InGaAsP/InP MQW mode-locked semiconductor laser and ultra-short pulse generator technology is presented, and according to which establish InGaAsP/InP MQW mode-locked semiconductor lasers theoretical model for further practical to provide experimental data; Thirdly, we establish InGaAsP/InP MQW mode-locked semiconductor laser experimental device ,the experimental data are collated and analyzed. Finally, summarizing the paper . |