Zero-power-gain measurements in cw HF(DF) laser by means of fast-scan technique. Interim report
An improved technique for measuring zero-power gain in a cw HF-DF chemical laser has been developed in which a cw HF(DF) single-line, frequency-stabilized TEM00 mode probe laser is used. Through use of a flat rotating mirror and focusing elements, the streamwise distribution of zero-power gain was scanned at a rate of approximately 1 mm/..mu..s with a spatial resolution of approximately 1 mm. The method, therefore, permits real-time observations of the streamwise gain profile. The zero-power-gain profile was observed for two-arc-driven chemical-laser nozzles with both HF and DF active species. The nozzles consisted of a 36-slit array with perforated tube H/supmore »