Editing Diffraction (section)

=== Diffraction grating ===
{{Main|Diffraction grating}}

[[File:Diffraction grating demo.webm|thumb|Diffraction grating]]

A diffraction grating is an optical component with a regular pattern. The form of the light diffracted by a grating depends on the structure of the elements and the number of elements present, but all gratings have intensity maxima at angles ''θ''<sub>''m''</sub> which are given by the grating equation
<math display="block"> d \left( \sin{\theta_m} \pm \sin{\theta_i} \right) = m \lambda,</math>
where <math>\theta_{i}</math> is the angle at which the light is incident, <math>d</math> is the separation of grating elements, and <math>m</math> is an integer which can be positive or negative.

The light diffracted by a grating is found by summing the light diffracted from each of the elements, and is essentially a [[convolution]] of diffraction and interference patterns.

The figure shows the light diffracted by 2-element and 5-element gratings where the grating spacings are the same; it can be seen that the maxima are in the same position, but the detailed structures of the intensities are different.