Efficient lasing on multiple-selected lines has been recently demonstrated experimentally on a cw hf chemical laser. Multiple-selected-line operation is required to both enhance atmospheric transmission and to ensure high-power extraction efficiency on multiple vibrational hf levels. Seventy-five percent of the multiline power was measured on two selected hf lines using a confocal, unstable cavity with a high-efficiency (97%) intercavity diffraction grating. This measured fraction of the multiline power is consistent with theoretical calculations, which include the effect of rotational nonequilibrium. The two-selected-line hf unstable cavity was not prone to parasitic oscillations. A novel multiple-selected-line integral master oscillator power amplifier (IMOPA) concept was also evaluated. Line selection on two hf lines was demonstrated with the IMOPA, although the hole diameter had to be made sufficiently large to prevent parasitic oscillations within the amplifier. It was concluded from our experiments and theoretical calculations that, although the IMOPA concept was demonstrated at relatively low power (400 W), parasitics may be a problem at much higher values of the single-pass gain.

Date Published: 1 April 1994
PDF: 9 pages
Proc. SPIE 2117, Modeling and Simulation of Laser Systems III, (1 April 1994); doi: 10.1117/12.171680

Published in SPIE Proceedings Vol. 2117:
Modeling and Simulation of Laser Systems III
Alvin D. Schnurr, Editor(s)