Diffraction of Light — Formula Sheet

First minimum condition: e sin θ = λ

General condition of minima: e sin θ = ± m λ

Condition for mth subsidiary maximum: e sin θ = (2m + 1)(λ/2)

Angular spread of central maximum on one side: sin θ = λ/e

Angular width of central maximum: 2θ = 2 sin⁻¹(λ/e)

If slit width e equals wavelength \u03bb, the first minimum occurs at \u03b8=90\u00b0, so the central maximum fills the whole space.

First minimum condition is e sin θ = λ.

The first minimum occurs when e sin θ = λ, and the general condition is e sin θ = ± m λ, where m = 1, 2, 3, ... .