Plane Diffraction Grating with 1200 Grooves. Specifications: Material : N-BK7 Size : 30mm x 30mm Wavelength : 400nm to 1000nm Grooves(Line/mm) : 1200L/mm Blazed Wavelength : 500nm Blazed Angle : 17.4 degree Clear Aperture :90% Except plane diffraction grating, we also have holographic diffraction grating. Realpoo Optics is a professional manufacturer of optical glass lenses, such as Spherical Lens, Glass Rod, Fresnel Lens, Optical Window etc. The optics can be offered with coating or without coating. Welcome to send your inquiry.