Design And Study On Novel High-Performance Long-Wavelength Pin Photodetectors

As global data service growing at an explosive rate, it is an inevitable trend to build a super-capacity broadband integrated services digital network (ISDN). Widely used wavelength division multiplexing (WDM) technology extremely improves data transmission capacity of fiber, and provides a useful way to realize the ISDN. Long-wavelength PIN photodetector is one of the key devices in WDM receive system. In order to improve its performance, this dissertation designs An In0.53Ga0.47As/InP drift-enhanced multiple-junction PIN photodetector as well as a novel integrated high-performance long-wavelength PIN photodetector with high quantum efficiency, narrow linewidth, flat-top steep-edge spectral response.The main research work and achievements are as below.1. Transit-time-limited response, RC-limited response, the total normalized response,3dB bandwidth, quantum efficiency as well as bandwidth-efficiency product (BEP) are analyzed for traditional drift-enhanced In0.53Ga0.47As/InP photodetector. For different p-n junction areas (10×10μm2,20×20μm2,30×30μm2,40×40μm2), the relationship between bandwidth-efficiency product (BEP) and thickness of absorption layer is studied. As p-n junction area becomes larger, BEP performance gets worse. For a certain junction area, as the thickness of absorption layer increasing, BEP increases gradually to a certain peak value and then decreases, which means there is an optimized thickness to maximize BEP. 2. On the premise of not to substantially increase fabrication difficulty level, a high-performance long-wavelength Ino.53Gao.47As/InP multiple-junction PIN photodetector is designed. For different p-n junction areas(10×l0μm2,20×20μm2,30×30μm2,40×40μm2), the optimized p-n junction numbers are3,2,2,1, the optimized thicknesses of absorption layers are0.54μm,0.84pm,1.16μm,1.28μm, and the maximized BEP are40.79GHz,25.47GHz,18.67HGz,15.62GHz, respectively.3. The key structure of a flat-top steep-edge PIN photodetector is the flat-top steep-edge filter. Novel1.55μm flat-top steep-edge one-cavity guided-mode resonant filter and two-coupled-cavity guided-mode resonant filter are designed.4. Novel1.55μm flat-top steep-edge PIN photodetectors are designed based on one-cavity as well as two-coupled-cavity guided-mode resonant filters, the peak quantum efficiencies are both90%, spectral response of the latter is close to a rectangular shape. Sideband values are extremely low (much less than5%).5. InP-based long-wavelength three-layer guided-mode resonant mirror is the key structure in one-cavity/two-coupled-cavity guided-mode resonant filter. The influences of grating cycle, grating depth, thicknesses of homogeneous layer-1and layer-2on its reflectivity are studied.6. A double-junction PIN photodetector with an integrated GaAs-based GaAs/AlGaAs DBR mirror is fabricated and a quantum efficiency measurement experiment is conducted. On the other hand, the fabrication procedures of the novel flat-top steep-edge photodetector and its binary embedded InGaAsP/InP grating are investigated, challenges are pointed out.