Grating prism

A grism is an optical component that a diffraction grating with a prism combined. In English it is also called “ grism ” ( grating + prism ) for short .

Grating prisms are mainly used in low-resolution spectrographs . The grating serves to split the wavelengths. The prism compensates for the deflection for a certain diffraction order and central wavelength . This makes it easy to switch between different grating prisms or filters without realigning the detector .

Web link

• Robert Grange, Bruno Milliard: Grism developments for space- and ground-based astronomy. SPIE Newsroom, July 6, 2011, doi: 10.1117 / 2.1201106.003739 .
• RW O'Connell: State-of-the-Art Spectroscopy. (Lecture Notes, with Hubble spectra of distant galaxies)