Holographic diffraction gratings have a sinusoidal groove shape, created by recording interference fringe fields in photoresist material. Since the grooves are symmetric, they do not have a preferred blaze direction. The range of useful diffraction efficiency is controlled by varying the modulation (the ratio of groove depth to groove spacing). Holographic gratings contain no periodic errors or “ghosts” as they are generated optically.

Plane Holographic Diffraction Grating has 1200 grooves per millimeter and a nominal blaze wavelength at 220 nm. It has a recommended spectral region of 190 to 800 nm. This 12.7 x 12.7 mm grating is aluminum coated on a 6 mm thick glass substrate.

Holographic Plane Gratings