Photonics Dictionary: S

The slits in a spectrograph that form images of spectral lines. Slits may be bilateral or unilateral, and generally close down to 0.01 mm and open up to almost a whole millimeter. The edges of the...

An aperture, usually rectangular in shape, with a large length-to-width ratio, and a fixed or adjustable shape through which radiation enters or leaves an instrument. The aperture is generally small...

The error inherent in spectral energy or spectrophotometric quantity due to the finite dimension of the entrance and exit slits.

An optical instrument for forming the spectrum of a light source and recording it on a film. The dispersing medium may be a prism or a diffraction grating. A concave grating requires no other means...

An instrument in which an image of the sun is scanned by the entrance slit of a monochromator, the exit slit simultaneously scanning a photographic plate for analysis of the solar spectral lines. If...

An instrument similar to the spectroheliograph, but having a scanning method that is performed by a pair of rapidly oscillating slits or a rotating glass block located before a pair of fixed slits at...

A high-contrast transparency of the gas sought, or an array of exit slits that correlates with some features of the spectrum. No standardized formula for positioning, number or thickness has been...