Diffraction of light

The phenomenon of the deviation of light from the rectilinear direction of propagation, which is not caused by reflection or refraction. It occurs on obstacles that have a size comparable to the wavelength of light.

two-slit diffraction

What is important is the passage of light through the slit, which according to Huygens' principle is the source of elementary waves.

The optical grating is formed by a large number of parallel scratches on the glass (up to 1000 per 1 mm), where the intact places represent the slits and scratches of the gap between them.

d · sin α = k · λ
d = lattice constant (slit spacing), α = the angle of the outgoing rays, k = order of the bending maximum, λ = wavelength of light

It follows from the equation that when white light passes through interference, a bending (lattice) spectrum is created, where red light is deviated the most and violet light the least.

Sources

  • KUBÁTOVÁ, Senta. Difrakce (ohyb) světla [online]. [cit. 2010-09-03]. <https://uloz.to/!CM6zAi6z/biofot-doc>.