a photodetector

Abstract

The invention discloses a photoelectric detector, and belongs to a photoelectric detector with a protection circuit. The protection circuit (3) comprises a follow circuit (31), a comparison circuit (32) and an analog switch circuit (33). The output end of a transimpedance amplifier circuit (1) of the photoelectric detector is connected with the input end of the follow circuit (31), the output end of the follow circuit (31) is connected with the input end of the comparison circuit (32), a reference voltage signal is connected with the input end of the comparison circuit (32), the output end of the comparison circuit (32) is connected with the control end of the analog switch circuit (33), and a first port, a second port, a third port and a fourth port of the analog switch circuit (33) are connected to power supply circuits of a first photoelectric diode (PD1) and a second photoelectric diode (PD2) respectively. An operational amplifier and the photoelectric diodes in the photoelectric detector can be effectively protected against damage, and the service life of the photoelectric detector is prolonged.

Description

technical field [0001] The invention relates to a photodetector, in particular to a photodetector with a protection circuit. Background technique [0002] Photodetectors are optoelectronic devices based on photodiodes and operational amplifier circuits, and are widely used in the measurement of laser noise in experimental systems of quantum optics and quantum information. [0003] Existing photodetectors for measuring laser noise such as Figure 4 , Figure 5 Shown, including photodiode, transimpedance amplifier circuit and operational amplifier circuit. In order to effectively detect the weak signal of laser noise, people often need a relatively large amplification factor of the transimpedance amplifier circuit in circuit design, but a new problem is introduced at this time, such as Figure 4 As shown, if the laser power irradiated on the two photodiodes has a large difference, the operational amplifier in the transimpedance amplifier circuit is easily in a state of output...

AI Technical Summary

Problems solved by technology

In order to effectively detect the weak signal of laser noise, people often need a relatively large amplification factor of the transimpedance amplifier circuit in circuit design, but a new problem is introduced at this time, such as Figure 4 As shown, if the laser power irradiated on the two photodiodes has a large difference, the operational amplifier in the transimpedance amplifier circuit is easily in a state of output saturation, which in turn causes the operational amplifier to be damaged due to overload; as Figure 5 As shown, if the laser power irradiated on the photodiode is too large, it will also cause damage to the operational amplifier in the transimpedance amplifier circuit, and even directly cause damage to the photodiode, thereby damaging the photodetector

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