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Light Detectors
Published in Roshan L. Aggarwal, Kambiz Alavi, Introduction to Optical Components, 2018
Roshan L. Aggarwal, Kambiz Alavi
Avalanche photodiodes (APDs) are photodiodes with an internal gain mechanism similar to a photomultiplier tube. A high reverse bias voltage is applied to the photodiodes to create a strong electric field. When an incident photon creates an electron-hole pair, the electric field accelerates the electron and holes producing secondary electrons and holes by impact ionization. The ionization coefficients αn and αp for the electrons and holes, respectively, increase rapidly with electric field values of the order of 105 V/cm. The avalanche multiplication factor is given by (Kingston 1995) () M=11−αw
Optical Receivers and Senders
Published in Abdul Al-Azzawi, Fibre Optics, 2017
Avalanche photodiodes (APDs) are high performance devices, and are widely used in many applications, such as optical communication, due to their high speed and internal gain. Although not as fast as p-i-n photodiodes, the devices offer superior receiver sensitivity in their own bandwidth range. The device bandwidth at high gain is limited by the gain-bandwidth product (GBW), for InGaAs-InP APDs. However, there are difficulties in fabricating the device; this process requires stringent process control. For this reason, commercial high performance APDs cost more than similar photodetectors.
Optical Receivers
Published in Abdul Al-Azzawi, Photonics, 2017
Avalanche photodiodes (APDs) are high performance devices and are widely used in many applications, such as optical communication, due to their high speed and internal gain. Although not as fast as p−i−n photodiodes, the devices offer superior receiver sensitivity in their own bandwidth range. The device bandwidth at high gain is limited by the gain-bandwidth product (GBW), for InGaAs-InP APDs. However, there are difficulties in fabricating the device; this process requires stringent process control. For this reason, commercial high performance APDs cost more than similar photodetectors.
Simulation study of front-illuminated GaN avalanche photodiodes with hole-initiated multiplication
Published in Cogent Engineering, 2020
Yangqian Wang, Yuliang Zhang, Yang A. Yang, Xing Lu, Xinbo Zou
III-N-based Avalanche Photodiodes (APDs) are of great interest for ultraviolet (UV) detection due to their low dark current density, high sensitivity, high optical gain, small size, and visible-blind characteristics (Jones & Kozlowski, 1993; Verghese et al., 1998; Wanyan et al., 2013). APD working in its Geiger mode is of particular interest when it comes to applications such as single-photon detection, photon counting, laser ranging, and so on (Verghese et al., 2001).