Spectra are given to illustrate the performance of echelette gratings made by the Merton-N.P.L. process, when used in a commercial spectrometer. The necessary instrumental modifications are described, and it is shown that one of these gratings, suitably blazed, can be used to cover the range 2.5–15µ with resolution greatly in excess of prisms of lithium fluoride, calcium fluoride, and sodium chloride, and at less than 5 percent of the combined cost of these prisms.
A. R. H. COLE, "Performance of Merton-N.P.L. Gratings in a Commercial Infrared Spectrometer," J. Opt. Soc. Am. 44, 741-743 (1954)