Demonstration of a Saturated Liquid Refrigerant Spray Cooling System for Laser Diode Arrays

Industrial-sized, solid-state lasers can not be scaled up in power to meet the demands of future missile defense systems due to stringent thermal constraints. Existing water-based thermal management systems are undesirable due to the high freezing point of water and need for military systems to operate in low temperature environments. Mainstream has recently completed a Phase I SBIR program that experimentally verified the potential for spray cooling high power laser diode arrays with non-water-based fluids. The patented system is capable of removing high heat flux at the laser diode array, maintaining spatially uniform temperature over large laser slab surface areas, and accurately controlling laser temperature. In Phase II a complete spray cooling thermal management system will be designed, fabricated, and integrated into a high-power, solid-state laser. The integrated laser system will be performance tested. In the Phase II Option, gravity-independence will be demonstrated for adverse-gravity and space-based applications. The result of this program is not just an incremental improvement over an existing thermal solution. It is the enabling technology that will make weapons-class, solid-state lasers a reality.