Fabrication of Diffraction Grating

A diffraction grating is a collection of reflecting elements separated by a distance. The grating divides every incident wave train into a multiplicity of wave trains of smaller intensities, and it causes the wave trains to emerge in certain preferred directions. Gratings are principally used in interferometers to create interference with the specimen grating, to study the deformation of the specimen.

Principle of a grating

The reflection grating consists of an epoxy grating on a glass substrate superimposed by a reflective surface such as aluminum. The glass substrate can be float glass or ultra low expansion (ULE) glass. Cross-line diffraction gratings with a frequency of 1200 lines/mm are made using a micro-replication technique using epoxies.