Diffraction Gratings

A diffraction grating is used in optical applications and is an optical component which diffracts and splits light into its separate wavelengths, to produce several beams travelling in different directions to the incoming beam. Gratings act as a dispersive element, and so the direction of the beams and resulting structural coloration is dependent on the spacing of the grating and wavelength of the incoming light. Gratings can be either reflective or transmissive and different gratings will cover the Ultraviolet, Visible or Infrared regions of the wavelength spectrum. Two main manufacturing techniques are used in the production of gratings and both require the production of a master grating which is used to produce replicas. Ruled Gratings are formed using a fine diamond tool that etches a series of grooves into the master grating, whereas the grooves on a holographic grating are manufactured using the interference fringe field of two laser beams. Diffraction gratings are used in the production of optical instruments such as spectrometers, lasers, optical pulse compressing devices and wavelength division devices.