A twelve-channel multiple-interferometer fabry-perot spectrometer.

A specialized spectrometer has been built to meet the time and spectral resolution requirements of a difficult plasma diagnosticexperiment. Two or three Fabry-Perot interferometers are arranged in series to provide the required spectral resolution and contrast.Twelve-channel output is produced by an annular mirror image dissector in the focal plane of the Fabry-Perot fringes. The spectralregion may be shifted by a change of gas pressure in the interferometer chambers. Measurements of the passband profiles with two interferometers are presented. Sample data from an experiment measuring the spectrum of ruby laser light after being scattered anddoppler broadened by a theta-pinch plasma are given.