All Problems

Diffraction of Light

Problem 5.127

Find the wavelength of monochromatic light falling normally on a diffraction grating with period \(d=2.2 \mu \mathrm{m}\) if the angle between the directions to the Fraunhofer maxima of the first and the second order is equal to \(\Delta \theta=15^{\circ}\).

Reveal Answer
λ=(dsinΔθ)/54cosΔθ=0.54μm\lambda=(d \sin \Delta \theta) / \sqrt{5-4 \cos \Delta \theta}=0.54 \mu \mathrm{m}