低噪声高带宽模拟光电探测器的设计和制作

Design and Fabrication of Analogical Photodetectors with Low Noise and High Bandwidth

分析了交直流同时响应的模拟光电探测器设计和制作中的关键问题,与电压差分光电探测电路相比,电流差分电路具有工作点始终稳定在零点、有效抵消PIN的噪声电流,以及无负载电阻的热噪声等优点,并找到了电流差分电路工作的最佳条件,制作了探测波长范围为900~1 700nm的模拟光探测器,其信噪比优于35dB,最小可探测光强为200nW,响应度为700V/W,响应带宽达到0~70MHz。

The key problems in the design of AC/DC response of photoelectric detector were analyzed.Compared with the voltage difference circuit,the current difference circuit owns such advantages as the operating point always stablizing at zero,suppressing the noise curent of PIN effectively and without the thermal noise of load resistance.Then based on finding the best operation conditions of current difference circuit,an analogical detector with the detection range of 900~1 700 nm was fabricated,with the signal-to-noise ratio of better than 35 dB,the minimum detectable light intensity of 200 nW,the responsibility of 700V/W,and the 3dB bandwidth of 0~70MHz.