These correspond to the diffraction orders ☑. Due to the grating's phase modulation, one can have additional reflected components with in-plane wave vector components. Ordinary reflection (as would occur at a mirror) would lead to a reflected beam having the in-plane wave vector component. In the simplest case of a sinusoidal phase variation, there are only two non-vanishing spatial frequency components with, where is the period of the grating structure.Īn incident beam with an angle against the normal direction has a wave vector component along the plane of the grating, where and is the wavelength. It is instructive to consider the spatial frequencies of the position-dependent phase changes caused by a grating. Note that there are also volume Bragg gratings, where the diffraction occurs inside the bulk material. This article treats mainly diffraction gratings where the diffraction occurs at or near the surface. However, there are also transmission gratings, where transmitted light obtains position-dependent phase changes, which may also result from a surface relief, or alternatively from a holographic ( interferometric) pattern. Most common are reflection gratings (or grating reflectors), where a reflecting surface has a periodic surface relief leading to position-dependent phase changes. It contains a periodic structure, which causes spatially varying optical amplitude and/or phase changes.
Light diffraction sheet how to#
How to cite the article suggest additional literatureĪ diffraction grating is an optical device exploiting the phenomenon of diffraction, i.e., an kind of diffractive optics. Definition: optical components containing a periodic structure which diffracts light