The Study On Avalanche Photodiodes With Several Multiplication Materials For Optical Communication

The paper study the frequency response, noise and sensitivity characteristics of avalanche photodiodes(APD). Recent years, separate absorption, grading, charge and multiplication avalanche photodiodes (SAGCM-APD), including InP/InGaAs,InAlAs/InGaAs and Si/Ge SAGCM-APD, draw a lot of attention in the field of optical communication. As optical communication systems push toward multigigabit per-second transmission rates, the noise and sensitivity characteristics of these APDs has become a critical issue. In this paper, using PSPICE software, noise and sensitivity characteristics has been studied systematically for APDs with different materials including InP/InGaAs, InAlAs/InGaAs and Si/Ge APD. Finally, the relation between the structure parameters of APD and noise and sensitivity of APD. The results is helpful to the design optimization of APD.In this paper, on basis of the circuit model, frequency response has been studied systematically for APDs with different materials including InP/InGaAs, InAlAs/InGaAs and Si/Ge APD and different structures such as normal incidence, waveguide and resonant. The effect of the thickness of the absorption layer, photo-sensitive area and parasitic parameters incident direction and voltage on frequency response has been addressed to APD. The simulation is in good agreement with the experiment, and compare with other materials, Si/Ge APD is the most promising candidate for high performance optical communication system, and waveguide and resonant APD has obviously advantage. In addition, our circuit model can be applied for circuit simulation software. Compared with simple circuit model of APDs, our circuit model is closed to the real APD's performance, it is helpful to the design optimization of APD.