Study on the Internal Mechanism of APD Photocurrent Characteristics Caused by the ms Pulsed Infrared Laser Irradiation

Liang Chen,Zhi Wei,Guang-Yong Jin,Di Wang

doi:10.3390/cryst11080884

Abstract

In this paper, the sampling current characteristics of the external circuit and the internal mechanism of the current generation in APD irradiated by a millisecond pulse laser were studied. The photocurrent of APD irradiated by a millisecond pulse laser with different energy densities was obtained by the sampling resistance of the external circuit. The photocurrent can be divided into a photocurrent stage, conduction stage and recovery stage in the time domain. This is mainly due to the carrier flow in APD, which leads to the lowering of the barrier between the PN junction. The research results of this paper can be extended to the response of the detector to the high-power infrared pulse laser and provide a certain experimental basis for the design of a millisecond pulse infrared laser detection circuit.

Highlights

As the main input port of detection and measurement systems, photodetectors have been widely used in optical tomography, communication, radar and other technical fields [1,2]
The multi-pulse 1064-nm laser that irradiated avalanche photodiode (APD) was researched, and the results showed that a multi-pulse did not affect the damage threshold when the repetition frequency was less than 1 Hz; when the repetition frequency was greater than 1 Hz, the damage threshold decreased with an increase of the number of pulses [7]
The peaks of the photocurrent are decreased while the laser energy density increases, and the peaks of the photocurrent are decreased while the laser energy density increases, and the peak time is basically the same

Summary

Introduction

As the main input port of detection and measurement systems, photodetectors have been widely used in optical tomography, communication, radar and other technical fields [1,2]. A. et al studied the characteristics of germanium avalanche photodiodes irradiated by a high-powered laser using a 4-ns pulse width and 1.064-um wavelength pulse laser [8]. It is of great significance to study the characteristics of the photocurrent and the mechanism of photocurrent generation when a pulsed infrared laser irradiates APD. The internal mechanism of photocurrent generation in APD irradiated by a millisecond pulse laser is studied for the first time. The microscopic mechanism of the barrier between the carrier and PN junction in APD is studied by the macroscopic representation of the sampling current. High-powered infrared lasers and provide a certain experimental basis for the design of the millisecond pulse infrared laser detection circuit

The wavelength the millisecond laser

Results and Discussion

Schematic

Conclusions