One very capable prospect for a compact, ultra-high-power laser source for military and other uses is the chemical oxygen-iodine laser (COIL; see www.laserfocusworld.com/articles/277162), which emits at 1.3 µm. A conventional COIL gets the iodine vapor it needs for its chemical reaction from a delivery system that evaporates the substance from solid iodine. Potentially simpler and more in line with the chemical nature of the laser itself, however, would be a process to generate the iodine vapor via a chemical reaction.
Researchers at the Chinese Academy of Sciences (Liaoning and Beijing, China) are doing just this, relying on an in situ reaction between chlorine and cuprous iodide (CuI). A gaseous mixture of chlorine and nitrogen is flowed over solid CuI and brought into the laser via polyimide injectors; the heat produced as the iodine is generated helps to prevent iodine precipitation. A square pipe-array jet-type singlet oxygen generator completes the fuel-supply system. The COIL achieved an output power of 7.8 kW at a chemical efficiency of 24.5%. Contact Yuelong Zhang at [email protected]