Transmission diffraction grating with antireflection coating has interrupted top layer for diffracting light, formed on two continuous uninterrupted layers on top of transparent substrate layer

摘要

The transmission diffraction grating has a transparent substrate layer (1). A non-diffracting antireflection coating has two continuous uninterrupted layers (2a,2b) formed on the top surface (1a) of the transparent substrate layer. An interrupted top layer (3) for diffracting light is formed on top of the antireflection coating. It consists of strips of transparent material of given thickness (d) given width (s), separated by gaps of equal width. The period (P) of the grating is 50 mu.