Polychromator

A polychromator is an optical device that is used to disperse light into different directions to isolate parts of the spectrum of the light. A prism or diffraction grating can be used to disperse the light. Unlike a monochromator, it outputs multiple beams over a range of wavelengths simultaneously. Monochromators have one exit slit and one wavelength at a time can pass through that slit. Polychromators have multiple exit slits, each of which allows a different wavelength to pass through it. A detector is placed after each slit so that the light at each wavelength is measured by a different detector. Polychromators are often used in spectroscopy.