Multikilowatt supersonic chemical oxygen iodine laser

The chemical oxygen iodine laser (COIL) is an attractive candidate for efficient power scaling at short wavelengths. High specific power output from supersonic operation leads to compact devices. The German Aerospace Research Establishment (DLR) started experimental investigations of a multikilowatt supersonic COIL at its Lampoldshausen rocket test site in 1994. The excited oxygen is produced by a rotating disk generator. Currently the laser is operated without a cold trap. After the injection of the iodine, the laser gas is expanded to an isentropical Mach number of 1.8 by a multi-element grid nozzle. At present, laser power at about 5 kW and radiation times up to one minute are realized. The paper discusses the general setup of the device and reports on some selected laser output characteristics.