基于虚拟仪器技术的APD噪声等效功率测量系统

Measurement system for the noise equivalent power of avalanche diode based on virtual instruments

利用锁相放大器测量雪崩光电二极管(APD)特定工作频率下的噪声电压,使用示波器测量APD在调制光输入条件下的电压值,使用功率计测量输入调制光能量值,以此测出APD的噪声等效功率(NEP)。并在测量过程中利用截尾平均数、变异系数等统计方法消除噪声干扰。同时,利用LabVIEW图形设计软件制作了一整套自动测试程序。实际操作表明,该测量系统测量具有精度高、操作简单、运行稳定可靠、自动化程度高等诸多优点,获得了科研人员的一致好评,具有较高实用性。

Lock-in amplifier is used to measure the noise voltage of APD（avalanche diode） under a specific operating frequency.And an oscilloscope is utilized to obtain the voltage of the APD optical modulated input.With the aid of an energy meter,the energy of the input modulated light is acquired for the measurement of the NEP（noise equivalent power） of the APD.To eliminate noise interference,some kinds of statistical methods such as the trimmed mean and the relative variance are adopted during the experiment.At the same time,the Labview software plays a vital role in designing the system for automatic test.Final results vividly prove that the designed system has a promising application with the excellent advantages of high measurement accuracy and control precision,good stability and reliability,high automation level and convenient operation.