Avalanche photodiode gain stabilization control device and method

Abstract

The invention discloses an avalanche photodiode (APD) gain stabilization control device and an APD gain stabilization control method. The device consists of a bias control circuit, an APD detection circuit, a data acquisition card and a computer; and the control method comprises the following steps that: the computer directly judges difference of an average digital signal acquired by the data acquisition card and a set signal value and transmits an APD bias regulating command, and the APD bias voltage is fed back and controlled through the bias control circuit; the whole device forms a closed loop feedback system; and the APD amplifier gain is finely adjusted so as to fulfill the aim of stabilizing the acquired digital signal. The invention has the characteristics that: the complexity and unreliability of a method for controlling APD temperature to be constant or a temperature-based feedback bias control method are avoided, the stability and reliability of the acquired digital signal can be easily and effectively improved, and the method is direct, effective, simple and reliable and has high practical and commercial values.

Description

technical field [0001] The invention belongs to the field of intelligent control, and is a control device and a control method for stabilizing the gain of an avalanche photodiode, and particularly relates to dealing with the situation that the gain of the acquisition signal is unstable due to the gain change caused by the temperature drift of the APD. The method can make the acquisition signal To achieve the goal of stability within the system preset range. Background technique [0002] Avalanche photodiode (hereinafter referred to as APD) is a photoelectric device based on the internal photoelectric effect. The avalanche photodiode has the function of internal gain and amplification, and one photon can generate tens or even hundreds of photogenerated electron-hole pairs, thereby amplifying the optical power. Avalanche photodiodes operate under reverse bias. Under a certain range of reverse bias voltage, the higher the bias voltage, the more photogenerated electron-hole pa...

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Problems solved by technology

The method based on temperature control requires high precision of the temperature control device, so the cost is high; while the bias voltage control method based on temperature acquisition requires a very accurate temperature bias curve of the APD and an accurate working temperature of the APD, and due to the need to test The temperature of the APD, the temperature measurement system is also likely to interfere with the APD, the operation is complicated, and the reliability is poor

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