A recorder scans the irradiance across a two-beam Young's double-slit pattern on a…
PHYSICS · Multi-part · Fermi University Physics · Optics & Photonics · Interference and diffraction · Coherence and statistical optics
Optics and Photonics, Ch Two-beam interference and interferometry
Problem
A recorder scans the irradiance across a two-beam Young's double-slit pattern on a screen and reports these features of the trace: neighbouring bright fringes are centred 12.0 mm apart; each bright fringe reaches an irradiance of 3.6 mW cm−2; and the irradiance falls to exactly 0.4 mW cm−2 midway between neighbouring bright fringes. The light has vacuum wavelength 633 nm and the screen is L=2.00 m from the slits.
((a)) Find the fringe visibility V.
((b)) Find the ratio I1/I2 of the two beam irradiances at the slits (with I1≥I2).
((c)) Find the slit separation d.