基于光纤光栅地震检波解调系统的微弱信号检测电路设计

摘要

研究了并设计了应用于光纤光栅地震勘探系统的光电检测电路。宽带光源经光纤光栅传感器反射回来的布拉格信号波很微弱，这就对微弱信号的检测提出了一个很大的难题，也影响着整个地震勘探解调系统的检测精度。在对一般电路设计的思路基础上，研究和设计了可探测微弱信号的光电转换电路。经过实验证明，此电路的噪声仅为0.19 mV，从而提高了系统的解调精度和速度。%A photoelectric detection circuit used in fiber Bragg grating (FBG) seismic surveying system is re-searched and designed. The Bragg signal wave reflected by a fiber grating reflector from a broadband light source is very weak. So the detection of weak signal is very difficult and the detection accuracy of the entire seismic de-modulation system is also influenced. Based on the general circuit design idea, a photoelectric conversion circuit detecting weak signals is researched and designed. Experimental results show that the noise in the circuit is only 0.19 mv. So the demodulation accuracy and speed of the system are improved.