Spectrometer for temporal measurement of each output line of multiline HF lasers

Abstract

An indium–arsenide detector array installed at the focal plane of a grating spectrometer provides the time history of the intensity of each output line of multiline HF chemical lasers. The construction and calibration of this instrument are discussed, and representative data are presented. Line competition measurements are shown for a 200-W supersonic-diffusion-type HF laser; individual line outputs fluctuate more than total multiline output. The spectral effects of forward/reverse-wave competition on an unstable ring resonator operating at 350 W are detailed. Simultaneous single-line gain measurements on a multiline HF medium are demonstrated. Other applications of this useful instrument are discussed.