Diffraction Properties of Blazed Gratings Illuminated with Broad-bandwidth and Divergent Beam

Far-field intensity and diffraction efficiency of the blazed reflection gratings illuminated with broad-bandwidth and divergent beam are investigated. When the spectral width and divergence of the incident beam with a constant energy increase, the maximum intensity decreases, and the half width at e-2 of the maximum intensity becomes wider. Diffraction efficiency has no deterioration for the blazed grating with a proper groove shape even when the incident light contains a broad range of wavelengths and comes from a wide range of angles.