Knowledge Bank

Calculations are being carried out for families of Littrow and Czerny-Turner systems using a method described at the March 1961 meeting of the Optical Society of $America.1$ The Primary wave aberrations of the mirrors are found, and the effect of the distortion of the wave front when it is diffracted is included. The aperture stop is placed at the grating, and has a diameter of 10 cm. Various focal lengths (e.g., 05 m, 1 m, 2m) and slit lengths are used. Silts are displaced horizonatally or vertically relative to the grating, and may be curved both in and normal to the focal planes.