Modeling of a narrow band pass filter for Bathymetry light detection and ranging (LIDAR) system

In this work, a narrow band pass Fabry-Perot filter is designed which can be used in an airborne light detection (ALB) and ranging bathymetry. LIDAR is done by reflecting a pulse laser beam from a target and detecting the round-trip propagation time between the source and the target. ALB systems consist of Nd: YAG laser that emits the pulses at two different wavelengths such as 1064 nm and 532 nm. Infrared pulses at 1064 nm are reflected from the water surface and the green pulses at 532 nm which penetrates the water surface and are reflected from the ground. Filters are desirable to suppress the ambient light that is reflected by the surface of the water or an atmosphere which always enter the detector as a noise. The designed filter shows a high quality with an average transmission of more than 95 % at 532 nm which is considered as practically ideal for water penetration in typical coastal waters.