Wadsworth mounting

Wadsworth mounting

[′wädz‚wərth ‚mau̇nt·iŋ]
(optics)
A device in which light passes through a prism and is then reflected from a plane mirror; it has the effect of a constant-deviation prism.
A mounting for a diffraction grating in which the slit is placed at the principal focus of a concave mirror, so that the light falling on the grating is in a parallel beam; it greatly reduces astigmatism.