Diffraction Gratings
Custom Plane and Special Plane Reflectance Gratings are available on a custom order basis. Please Contact Us with your requirements.
A reflection grating is an array of fine, parallel, equally spaced grooves on a reflective substrate. When polychromatic light is incident on a diffraction grating, diffraction and interference effects spread the various wavelengths in discrete directions called "orders" or "special orders."
Because the angle of deviation of the diffracted beam is wavelength dependent, a diffraction grating separates the incident beam spatially into its constituent wavelength components. The groove dimensions and spacings are on the order of the wavelength in question. Order zero corresponds to direct transmission or specular reflection. Higher orders result in deviation of the incident beam from the direction predicted by geometric (ray) optics. With a normal angle of incidence, the angle θ, the deviation of the diffracted ray from the direction predicted by geometric optics is given by the following equation where m is the spectral order, λ is the wavelength, and d is the spacing between corresponding parts of adjacent grooves: mλ=dsinθ
By controlling the cross-sectional shape of the grooves, it is possible to concentrate most of the diffracted energy in the order of interest. This technique is called "blazing." The blaze angle is then defined as the angle of incidence that allows maximum concentration in the first order.
Custom Plane and Special Plane Reflectance Gratings are available on a custom order basis. Please Contact Us with your requirements.
