Details of two bilateral slits designed for use in an infra-red spectrograph are described. The widths of the slit openings may be continuously varied from 0 to 4 millimeters in one case and from 0 to 12 millimeters in the second case. The designs permit reproducible fine control of these widths.
Correct formulae for curvature of prism and grating images are given without derivation.
HERMANN ROEMER and ROBERT A. OETJEN, "Two Bilateral Spectrograph Slits," J. Opt. Soc. Am. 36, 47-51 (1946)