A Range-Gated Laser System for Ocean Floor Imaging

Abstract

We describe tank studies which show that a copper chloride laser is a good illumination source for a deep ocean imaging system. The laser is naturally pulsed (∼20 ns pulse width) at repetition rates of 10 to 20 kHz, and operates with high (1%) efficiency in the blue-green window for optimum transmission in water. A range-gated, scanning imaging system based on this laser can operate with input power of a few hundred watts, obtaining 100m wide digital image coverage of the sea floor from altitudes of 50 m. Measurements of range (bathymetry) and particulate matter distribution within the water column are also possible.