低噪声不隔直光电探测电路的设计

光电探测电路是光纤通信和光电检测系统中光信号转换成电信号的关键部分，但现有光电探测器大都不能同时测量脉冲光信号与直流光信号。为了获得低噪声并且能够同时测量脉冲光信号和直流光信号的光电探测器，设计一个不隔直光电探测电路，采用平衡放大方式消除直流工作点不稳定问题，提出了一种利用谐波分析法测量光电探测电路带宽的方法；同时对影响噪声的各种因素进行了研究，计算了探测电路的噪声电压和电流，提出了利用降低温度的方法提高信噪比。结果表明了该方法的有效性。

Low Noise and Non DC Blocking Photoelectric Detection Circuit Design

The photo detector is a key component that transform optical signal into electrical signal in the optical fiber com- munication and photoelectric detection system, but most existing photo detector can＇t measure the pulsed optical signal and the current optical signal simultaneously. In order to obtain a photo detector that low noise and capable of measuring pulsed optical signal and the current optical signal, a non 13（2 blocking optical detection circuit was designed. A balance amplification method was used to eliminate the instability problems of DC operating point. A method was proposed that measure the band- width of the photoelectric detection circuit through harmonic analysis method. The factors was studied that affect the noise, the noise voltage and current were calculated. A method was proposed to improve the SNR through lower temperature.