Modulated laser signal front-end processing technology

The paper presents a research on the front-end receiving circuit for processing the modulated laser signal. In order to get an overall understanding of optical filtering, some knowledge about the light collection and the spatial filtering is discussed firstly. Subsequently, to improve the design of front-end circuit, several traditional laser receiving circuits are completely studied, and the advantage and the disadvantage of each circuit are summed up. On this base, furthermore, the TCVCC (Transimpedance current-to-voltage conversion circuit) with parallel LC feedback is put forward and explored. To verify the TCVCC with parallel LC frequency selective network, in detecting and recognizing weak modulated laser signal, is superior to the traditional laser receiving circuit, and an experiment is carried out finally. The experiment results show it is capable to extract the weak modulated laser signal from the strong noise.