Diffraction Gratings

Diffraction gratings separate white light into component wavelengths. There are two grades of Diffraction Gratings. The research range which is of high-quality replica reflection gratings and includes both ruled and holographic types. Generally ruled gratings have higher efficiency, while holographics have lower stray-light levels and are available in closer rulings. For the UV, however, blazed holographics are available with a similar profile and efficiency to ruled types. Efficiency curves are available on request.

The commercial ranges are inexpensive transmission replicas mounted between glass plates and are suitable for simple demonstrations etc.

Specific Requirements
We can manufacture Diffraction Gratings to any size at short notice, so if your requirements are not listed please contact us by telephone / fax or email: stockrequirement@knightoptical.co.uk

Data for calculation
Light of wavelength λ incident at an angle I will be diffracted at angles i’ given by:

Sin i’ = Gnλ–sin i

Where G=groove density (lines/mm) and n is the order of diffraction (any integer). Blazed gratings have facets inclined at an angle b to the surface to concentrate light into the first order (n=+1). When the grating is used in the Littrow condition (retroreflection, i=i’) peak efficiency will be near the blaze wavelength shown (= (2/G) sin b).

Options available
  · Other wavelengths
  · Other sizes, or stock can be cut down to other sizes and shapes
  · Other coatings, transmission types etc. available to order