Intracavity solid state Raman marine transmitters

ABSTRACT The design and performance of a short-pulse (1.5 ns), high-energy (90 niT/pulse) nonlinear cavity-dumped, frequency-doubled, solid-state intracavity Raman laser is presented. The laser described is utilized as the transmitter in a high-resolutiongurf-zone marine imaging lidar system.Keywords: Raman, Barium nitrate, LBO, Marine lidar. 1. INTRODUCTION The perfomiance of contemporary lidar systems may be characterized by the signal-to-noise ratio (SNR) achievable by the system. Defining the SNR' to be the square of the mean signal level divided by the mean square noise level, the expression for SNR is: SNR = (s —B)2 pixels (1)where S is the mean number ofphotoelectrons per pixel produced by the image of the submerged target of interest, B is themean number of photoelectrons per pixel produced by the image of the water backscatter around the target, N is the meansquare noise level in photoelectrons per pixel and #pixels is the total number of pixels subtended by the target in the image.For shot noise limited detection, the mean square noise level is given by the mean background level. B. For a pulsed lidarsystem with outgoing pulse energy of E, a collection optic with entrance pupil area of A1,, and n1 for the total number ofpixels in the image, S is given by: