Explain diffraction grating effects.
Explain diffraction grating effects.
A diffraction grating is an optical device or element which separates (disperses) polychromatic(multi-wavelength) light into its constituent colors (wavelengths). The polychromatic light incident on the grating is dispersed so that each wavelength is reflected from the grating at a slightly different angle. The dispersion arises from the wave-front division and interference of the incident radiation from the periodic structure of the grating.
A diffraction grating consists of a large number of evenly spaced parallel slits that produce an interference pattern similar to but sharper than that of a double slit. In double-slit, there are only two slits by which light passes towards the screen but in the diffraction grating, an infinite number of slits are present by which polychromatic light passes.
The dispersion of a grating is governed by the grating equation, usually written as:
where: n is the order of diffraction,
λ is the diffracted wavelength
d is the grating constant (the distance between successive grooves)
θi is the angle of incidence measured from the normal and
θd is the angle of diffraction measured from the normal.
Step by step
Solved in 3 steps with 2 images
