Two coherent beams from a beam splitter recombine on a screen

PHYSICS · Subjective · Fermi University Physics · Optics & Photonics · Interference and diffraction · Interference and diffraction

Optics and Photonics, Ch Two-beam interference and interferometry

Problem

Two coherent beams from a beam splitter recombine on a screen. Their irradiances, measured separately with the other beam blocked, are

I_1 = 9.0

mW cm

^{-2}

and

I_2 = 4.0

mW cm

^{-2}

. Find the fringe visibility

\mathcal{V} = (I_{\max}-I_{\min})/(I_{\max}+I_{\min})

of the pattern.