Application of Fabry-Perrot modulator to modulated LIDAR system for underwater detection

摘要

Frequency spectrum characteristics of the seawater show that backscattering signal has a low-pass characteristic while target reflection signal is less frequency-dependent. To improve target contrast of underwater detection, LIDAR signal is modulated to radio frequency band by Fabry-Perrot modulator. As a result, target reflection signal is bigger than backscattering signal at the modulation frequency. Through the comparison of the target contrast, we find that the best modulation frequency is about 2 GHz and the target contrast improves more than 14 times.