Analysis Of High Performance Photodetector And Its Measure Method

In recent years, researches on high-performance photodetectorhave played a key role in improving the communication quality of optic fiber communication system, and kinds of novel photodetectors have been developed. Given the demands of large communication-capacity and high communication-quality communication system, opportunities and challenges both exist for photodetector. This dissertation mainly focuses on the research of performance analysis and measurement method for high-performance photodetecotor. The main research works and achievements are as follows:1.The common high-performance photodetecorand the future of photodetector were introduced.In addition, the theoretical analysis of the parameters which are used to evaluate the quality of photodetector was developed.The optimal method for improving the bandwidth-efficiency product of the photodetectorwas also discussed.2. A novel design scheme to improve the responsivity by modifying the confinement factor of the guided beam was proposed. For such a design scheme, the top ridges width varies along the length of the waveguide. As such,the optical confinement factor varies as the light propagates in the waveguide, and the responsivity of phototdetector is improved accordingly. In this scheme, responsivity of0.98A/W was achieved. In addition, as the transit-time in absorption layer is essential for the scheme to achieve a high speed responsibility, we also discuss the thickness of the absorption layer. With an absorption layer thickness of100nm and an intrinsic layer thickness of1.6μm,3dB bandwidth of32GHz was achieved.3. Analysis of the microwave performance of photodetector using the two-port network modeland the calculation methods of the scatter matrix of photodetector was proposed.The electrode of photodetectorwas optimized and an optimal thickness of substrate(345nm) was achieved by using the simulation software.4. The spectral response and frequency response measurement system of photodetector was built, and the frequency response was measured in sweep frequencies.method and optical heterodyne method.The simple error analysis modelwas also developed.