To address this need, Aqwest developed high-performance, ultra-rigid, isothermal heat exchangers for cooling of large area laser gain elements, non-linear crystals, and high-power optics.  Our heat exchangers use water-cooled microchannels or microjets to deliver very low and spatially uniform thermal resistance.  For high-end weight-sensitive applications, we use single-crystal silicon substrate offering high thermal conductivity, low CTE, and high Young’s modulus.  Such heat exchangers maintain optical figure under high thermal load. For soldering to laser crystals and optics, we use CTE-matched heat exchanger materials.  Interface to the heat load can be maintained isothermal to 1°C. The interfacing surface can be also machined to a quality suitable for optical contacting, which offers excellent heat transfer.  The development of the Aqwest heat exchanger was in-part supported by the US Army, DARPA,  and the US DOE.