Scalable and stable, cw photolytic atomic iodine laser

Abstract

The scalable and stable, cw photolytically excited atomic iodine laser operates at 1.315 nm. An initial power level of 55 watts/liter was obtained via the cw photolysis of an alkyl-iodide gas like C.sub.3 F.sub.7 I. The greatly enhanced laser performance was achieved using a microwave excited, electrodeless Hg plasma lamp excited with a d.c., low ripple cw microwave radiation. Both high flow, air cooling and liquid dimethyl polysiloxane cooling of these high pressure Hg lamps provided long lifetime operation with the latter promoting, stable laser operation. Transverse flow of the above gas for the removal of the quenching by-product I.sub.2 is incorporated into the laser. To insure good laser amplitude stability, both the high power magnetrons and the lamps are liquid cooled. The scalable, prolonged and stable operation of this laser system is possible via use of a closer cycle, condensative/evaporative fuel system coupled to a high flow, internal blower for heavy gases. Over the excitation length of 25 cm, an average small signal gain coefficient of 2%/cm. is produced by exciting the transversely flowing gas from one side. Higher powers are achieveable by exciting the gas from both sides, increasing the ultraviolet lamp radiation with higher microwave power and/or more efficient UV operating plasma lamps, and/or adjusting the UV lamp emission into the C.sub.3 F.sub.7 I absorption in the 240-320 nm region.