A single-layer antireflection coating of magnesium fluoride ( ) is to be deposited on…
PHYSICS · Multi-part · Fermi University Physics · Optics & Photonics · Interference and diffraction · Interference and diffraction
Optics and Photonics, Ch Multiple-beam interference: thin films, multilayers and the Fabry-Perot etalon
Problem
A single-layer antireflection coating of magnesium fluoride (nf=1.38) is to be deposited on a flint-glass lens of refractive index ns=1.60, for use at λ=620 nm at normal incidence in air (n0=1.00).
((a)) Find the refractive index that would give exactly zero reflectance at this wavelength, and state whether magnesium fluoride achieves this.
((b)) Find the thickness of the magnesium fluoride layer that makes it a quarter-wave coating at λ=620 nm.