Izentis offers gratings thatutilize reflection from periodicsurfaces, known as a reflection gratings. If the surfaces are flat, reflectiongratings are similar to phase transmission gratings. Specifically much of the light isin the zeroth order. The key break-through for reflection gratings is to reflect thelight on angled mirrors (often called grating facets) such that the diffraction orderscoincide with the specular reflection angle. This effect is knows as blazing and itcan significantly increase efficiency since the majority of the light is directed into asmall number of non-zero diffraction orders.The angle αhas to be designed such that the optical path length difference for tworays, that specularly reflect one period apart, is an integer multiple of the wavelength. Izentis LLC offers custom reflection gratings with facet angles ranging from 0.5 to 30 degrees, with pitches as low as 200 nm. The grating dimensions can be as large as 60 mm on a side. Please contact us for more information and quotes on reflection gratings.
Conceptual drawing of blazed reflection gratings and the grating equation.
Scanning electron micrograph of 200 nm-pitch blazed reflection grating with 15 degree facets, fabricated by Izentis.