Based on the design of APD-weak laser signals detection circuit

摘要

As a highly accurate measurement method, Electro-optical detection technique played a key role in many fields. Weak signal detection has been restricted the Electro-optical detecting equipment monitoring ability. The studies of how to improve the photoelectric device for weak signal detection and extraction ability, photoelectric devices work level and strengthen monitoring ability have the great significance.According to the characteristics of APD photoelectric diode, the laser signal detection circuit has been designed so that the weak laser signal detection can be realized. The principle of APD photoelectric diode, the noise coefficient and working conditions have been introduced, by using PWM devices, the APD high-voltage bias circuits can be designed which has wide range output voltage and continuous adjustable characteristics. The APD amplifier circuit also can be designed; it mainly introduced three aspects when take consideration on amplifier circuit design, including the bandwidth, magnification and input impedance. Through the analysis of noise characteristics and laser pulse signal characteristics, detection circuit noise can be curbed and SNR can be improved, they all contribute to building up a higher sensitivity of laser signal detection circuit. Detection circuit is applied to laser range finder, laser monitoring and so many various applications.