High Heat Flux Laser Diode and/or Solid State Laser Cooling for Airborne and/or Spaceborne Directed Energy Applications

"Diode lasers present one of the most challenging thermal problems in industry. The small footprint and the very high power levels combine to create extremely high heat fluxes (0.5 - 10 kW/cm2) in the vicinity of the diode. These heat flux levels raisethe diode temperature, leading to lower lasing efficiency, wavelength shifts, and reduce diode lifetime. The cooling problem becomes even more difficult when combined with requirements for low pressure drops, reliability, long operating life, ease ofattachment, small volume, and low cost.The best performing thermal management solutions available in the marketplace today are provided through micro-impingement and microchannel cooling methods, which offer thermal resistances as low as 0.035 K-cm2/W. Many customers, however, have expressedinterest in even higher levels of thermal performance. To achieve improved performance levels this Phase I study will examine the addition of microfins to the cooling channels, and operation in the flow boiling regime. microVection has also developed aproprietary matched thermal expansion microchannel cooling approach which will also be evaluated during the Phase I program. The existing microchannel cooler market is rapidly growing and can make immediate use of the cooling enhancements proposed here.Other high heat flux systems such as high power elecrtronics or hypersonic vehicle components can also benefit from the proposed work."