Northrop Grumman Cutting Edge Optronics (St. Charles, MO) has developed a new type of ceramic-based microchannel cooler for high-power laser-diode arrays that works better than existing copper-based designs. The patent-pending cooler design uses layers of ceramic material for long lifetime and ability to operate in harsh conditions, with thermal performance comparable to standard copper microchannel-cooled packages and without the possibility of internal corrosion. Because the coolant is electrically isolated from the current path in an optoelectronic device, it is not necessary to use de-ionized water; standard filtered water is adequate.
Because of the robustness of the ceramic material and the close match of its coefficient of thermal expansion with that of standard semiconductor laser materials, gold-tin solders can be used in package assembly rather than less-robust indium solders. This further improves performance compared to copper microchannel coolers. The coolers have been created in linear, vertical, and two-dimensional stacks for direct-diode and solid-state laser pumping requirements; custom coolers can be designed for applications with unique bar-to-bar pitch or pressure/flow requirements. The new coolers will be on display at Photonics West 2009. Contact Ryan Feeler at [email protected].