EFFICIENCIES FOR INFRARED GRATINGS

Author Institution: The Perkin-Elmer CorporationThe increased use of gratings in infrared spectrophotometers has made it desirable to evaluate some of the properties of gratings. This paper describes the techniques and equipment used to measure the efficiencies of gratings (1 micron to 15 microns) relative to vacuum deposited aluminum. During standardization, it is possible to obtain a correction factor to yield absolute efficiency measurements. Some typical efficiencies of gratings will be shown as a function of frequency, polarization, blaze angle, grating angle and order used From these data, one can determine the useful range over which a grating may be used for a given order