Erratum: Construction of parallel grides acting as semitransparent flat mirrors in the far infrared [Rev. Sci. Instrum. 49, 926 (1978)]

Since publication of this paper, we became aware of the paper by Costley, Hursey, Neill, and Ward entitled “Free-standing fine-wire grids: Their manufacture, performance, and use at millimeter and submillimeter wavelengths” [J. Opt. Soc. Am. 67, 979 (1977)] and the fact that such wire grids are commercially available from the Spectroscopic Accessories Co., St. Mary Cray, Orpington, Kent, England.