Detection Of Key Performance Parameters Of Avalanche Photodiode For Visible Light Communication And Development Of Its Application Module

Avalanche Photodiode(APD)has high responsivity and signal-to-noise ratio due to its inherent avalanche gain,and has attracted much attention in the field of weak optical signal detection.In recent years,with the rapid development of visible light communication,high-speed and low-noise receiving ends are required.Compared with PIN,APD has obvious advantages in signal detection and subsequent circuit integration.However,the responsivity and quantum efficiency of silicon-based APD(APDs)in blue band are low.Therefore,based on the project's independent research and development of blue-sensitive APDs,this paper built a key performance parameters detection platform for APDs and developed its application module.The details were as follows:(1)The basic performance parameters detection platform of APDs was built.The four basic performance parameters of dark current,responsivity,avalanche gain and quantum efficiency were measured.The influence of incident light power on the responsivity was discussed.(2)A platform for detecting excess noise factor of APDs was built.In order to built the platform,a modulated laser and a printed circuit board(PCB)were fabricated,and the relative intensity noise of the laser was measured by APDs and PIN,respectively.and the noise introduced by the laser was subtracted during the detection of the excess noise factor.The experimental results showed that the excess noise factor detection scheme designed in this paper is feasible,but the platform needs to be further improved.(3)A 3d B bandwidth detection platform for APDs was built.The driver module of the optical transceiver module,transimpedance amplifier and impedance matching PCB were fabricated when the platform was built.It was found that the transimpedance amplifier has high requirements and uncertainties in the bonding technology and could not meet the requirements for detection.Therefore,the PCB and 50? load were used to successfully measure the 3d B bandwidth of the commercial APDs to 1GHz,which was consistent with the parameter specification..(4)The application module of the APDs detector with constant temperature control wasdesigned.The stability of the module and the influence of temperature on the basic performance parameters of APDs were measured.The average relative deviation of the three repeated measurements of the continuous insertion and removal of the fiber at room temperature was0.795%.The module was tested at 27.1°C,24.5°C and 20.4°C respectively.The results showed that the APDs gradually approached the breakdown voltage,and the avalanche gain increased with the decrease of temperature.By increasing the reverse bias voltage and reducing the temperature control temperature,it was more advantageous for weak light detection.