Monochromator

Definition

A monochromator is an optical dispersing device that is used to select a narrow band of light (i.e., optical radiation) from a wider range of wavelengths available at the input. The Greek roots “mono-” and “chroma-” refer to “single” and “color” respectively. Ideally, a monochromator should produce a single wavelength of optical radiation at its output. Although lasers produce light that is much more monochromatic than the optical monochromators discussed here, only some lasers are easily tunable but are not as simple to use.

Monochromators are included in many optical measurement instruments and systems for applications where tunable monochromatic light is required. A monochromator combined with optical detectors can be used to obtain the spectral power distribution (SPD) of light sources, reflectance or transmittance of objects, etc.

Monochromators are important for color measurement because many color-related optical characteristics are dependent on wavelength. In color...