grism

plural grisms

1. A combination of diffraction grating and prism used to obtain spectra from selected parts of an image.

   The advantage of grisms is that the same camera can be used both for imaging (without the grism) and spectroscopy (with the grism) without having to be moved.

   3 more examples

   If this grism is placed in an ƒ/4 beam at s = 120 mm, the plate factor P ≈ 1100 Å/mm.

   1987, Daniel J. Schroeder, Astronomical Optics, Academic Press, page 302

   As the name implies, grisms are a combination of a transmission grating and a prism. One common configuration uses the refraction at the grism surface to redirect nonzero diffractive orders along the original optical path.

   1994, T. M. Herbst, J. T. Rayner, “First Experiences With A Solid ZnSe Grism for Near Infrared Astronomy”, in Ian S. McLean, editor, Infrared Astronomy with Arrays, Springer,, page 515

   The grism usually consists of an SR transmission grating mounted on the hypotenuse of a right-angle prism.[…]Volumetric phase holographic grisms, which are capable of relatively high angular dispersions, have begun to appear.

   2010, Frederick R. Chromey, To Measure the Sky, Cambridge University Press, page 382

   Synonyms: grating prism