Young’s Double Slit Experiment

Young’s double slit © SPK

Path difference:

For a bright fringe, For a dark fringe, m: any integer

For two beams of equal irradiance (I 0 )

Visibility of the fringes (V) Maximum and adjacent minimum of the fringe system

Thomas Young's Double Slit Experiment

Photograph of real fringe pattern for Young’s double slit

The two waves travel the same distance –Therefore, they arrive in phase S S'S'

The upper wave travels one wavelength farther –Therefore, the waves arrive in phase S S'S'

The upper wave travels one-half of a wavelength farther than the lower wave. This is destructive interference S S'S'

Young’s Double Slit Experiment provides a method for measuring wavelength of the light This experiment gave the wave model of light a great deal of credibility. Uses for Young’s Double Slit Experiment

Fresnel double mirror P1 P2 © SPK

Fresnel biprism © SPK

Lloyd’s mirror © SPK

Billet’s split lens © SPK

For a bright fringe, For a dark fringe, Extra phase difference ±  in Lloyd’s mirror

Wavefront splitting interferometers Young’s double slit Fresnel double mirror Fresnel double prism Lloyd’s mirror

1. Optics Author: Eugene Hecht Class no. 535 HEC/O Central library IIT KGP