基于PIN光电二极管的光功率计

Design of Optical Power Meter Based on PIN Photodiode

设计了一种基于PIN光电二极管的功率检测计的硬件设计方法和程序流程,给出了其校准方法及数据修正方法。该光功率计采用PIN光电二极管实现信号的光电转换,通过对数比放大器进行前置的I/V变换及放大;采用16位A/D转换芯片AD7705保证了测量分辨率。单片机89C51作为主控制单元实现信号的检测与数据处理,并通过数据修正进一步提高了测量精度。实际测试数据和使用情况表明:该光功率检测计具有成本低、维护简单等优点,可获得-70～+10 dBm(0.1～10 mW)的动态范围、0.1 dBm的测量精度以及分辨率为0.01 dBm。

This paper designed a PIN photodiode based power meter testing methods and procedures for the hardware design process,then presented its calibration and data correction method.The optical power meter used PIN photodiode to meet the photoelec-tric conversion of signal,through I/V conver-sion and amplification of the front of amplifier,adopted 16-bit A/D conversion chip AD7705 to ensure accuracy.It used the microcontroller 89C51 to achieve signal detection and processing;further improve the measurement accuracy by data revisions.Actual test data and use condition indicate this optical power can meter with a low cost,easy maintenance,etc.,and can get the dynamic range from-70 dBm to ＋10 dBm（0.1 nW to 10 mW）,the measurement accuracy during 0.1 dBm and resolution of 0.01 dBm.