Hinge spectrometer: a grating Fabry-Perot instrument for far-infrared/submillimeter spectroscopy in space.

A compact submillimeter spectrometer can be constructed through the use of a combination of grating and Fabry-Perot techniques. The instrument has only one moving part, a grating that pivots about an accurately placed hinge. The entire optical train is cooled to liquid helium temperature for low-background low-noise operation and is designed for use in astronomical observations from aircraft, balloons, or space vehicles. Resolving power R ~ 20,000 at ~ 150microm is demonstrated.