Rare‐gas halide lasers

The rare‐gas monohalides are simple diatomic molecules whose properties and emission spectra were essentially unknown as recently as four years ago. Now they are the active media for gas lasers that could provide overall electrical efficiency as high as 10%. These lasers operate in the ultraviolet and vacuum‐ultraviolet spectral regions and are the first lasers outside the infrared region that appear to be scalable to high single‐pulse energy (greater that 100 joules per pulse) with high average power and efficiency. Not surprisingly in light of the species' novelty and the laser's promised utility (for example, in photochemical‐separation schemes), research and development in this area has grown remarkably since the first laser demonstration three years ago.