Design Of The High Gain And High Saturation Vertical Cavity Semiconductor Optical Amplifier Used For Intergrating With PIN Detector

With the rapid development of the optical communication systems, higher requirementsare proposed regarding the performance of the optical components. In the long-haul,high-bit-rate optical communication systems, photodetector, the main device of opticalreceiver is used to receive the carrier modulated by optical signal, and demodulate thetransmission information through the photoelectric conversion. Therefore, its performancedirectly affects the whole optical communication systems. Photodetector mainly include PINphotodiode and avalanche diode (APD). At high bit rate, the sensitivity performance of thesetwo kind of receivers is limited. But the scheme of preamplifier combined with PIN canmake the amplification of optical signal without the bandwidth limit, thus can be used as aneffective scheme to realize a high speed and high sensitivity photoelectric detector.Main researches of this thesis are as follows:(1) This thesis analyzes the advantage of substituting the optical preamplifier+PIN forAPD. Further more, we discuss how to choose the appropriate optical amplifier. Here weprefer vertical cavity semiconductor optical amplifier (VCSOA). Due to the circular beam ofoutput, it is easy to couple with the PIN detector, and the polarization is independent withgain; in addition, the vertically integrated structure is easy to realize a high density2D arrayand can be cost-effectiveness.(2) It analyze the structure of VCSOA and its principle. Due to the short optical cavity,in order to get higher gain, we need to consider how to improve the single trip gain of thecavity and how to improve the feedback of both ends.(3) It give a modeling of this device. Including the transfer matrix method forcalculating the DBR reflection spectrum, and the traveling wave equation method forcalculating the output characteristics of optical amplifier.(4) It analyze the characteristics of VCSOA through the simulation and study thefeasibility of VCSOA+PIN integrated device. According to the different applications, wedesigned two kinds of VCSOA in detail:1) By optimizing the VCSOA gain, and using themethod of integrating preamplifier and PIN, we can improve the sensitivity of receiver onthe premise of guaranteeing high bandwidth, and then we can replace the APD with it;2) By optimizing the gain saturation characteristic of VCSOA (still the VCSOA+PIN structure),the optical power equalization of the received signal can be realized, and we can reduce thelarge dynamic range of input power in passive optical access network due to differenttransmission distance optical line terminal (OLT) and optical network unit (ONU).