Noise characteristics improvement of submicron InP/InGaAs avalanche photodiode for laser detection system

InP/InGaAs avalanche photodiodes have attracted much attention in optoelectronics and long distance optical communication systems due to their high bit rate and gain-bandwidth. In this paper, to improve the noise characteristics in laser detection systems, separate absorption, grading, charge, and multiplication InP/InGaAs avalanche photodiode (SAGCM APD) with double guard rings and three thin layers of InGaAsP has been simulated. In addition, the multiplication width of SAGCM APD has been optimized which enhances the noise characteristics. The Photocurrent and dark current are acquired as 40μA and 0.01 nA resulting in superior electrical properties among the other works. The excess noise factor in the constant mean gain of 10 has been reduced 10.3% in comparison with recent SAGCM APDs. The calculated results show that the reduction of dark current and the excess noise factor increase the SNR for about 5 orders of magnitude.