Microchannel-cooled heatsinks for high-average-power laser diode arrays

Detailed performance results for an efficient and low thermal impedance laser diode array heatsink are presented. High duty factor and even cw operation of fully filled laser diode arrays at high stacking densities are enabled at high average power. Low thermal impedance is achieved using a liquid coolant and laminar flow through microchannels. The microchannels are fabricated in silicon using an anisotropic chemical etching process. A modular rack-and- stack architecture is adopted for heatsink design, allowing arbitrarily large 2-D arrays to be fabricated and easily maintained. The excellent thermal control of the microchannel heatsinks is ideally suited to pump array requirements for high average power crystalline lasers because of the stringent temperature demands that are required to efficiently couple diode light to several-nanometer-wide absorption features characteristic of lasing ions in crystals.