Monochromators

Monochromators are spectrometer optical systems capable of measuring a single wavelength, which can be scanned through a wide wavelength range. A common form of monochromator is the Czerny-Turner design, consisting of fixed entrance and exit slits, fixed focusing mirrors, and a rotatable diffraction grating. As the grating rotates, a different wavelength is focused onto the exit slit. The wavelength range of a monochromator varies with the choice of grating, but commonly they can scan from 160 nm to 500 nm or ever wider ranges. The spectral resolution depends on the widths of the slits and the choice of grating and focal length, but commonly can be less than 10 pm for high resolution OES.