An 18-mm-wide grating has rulings of 710 lines per millimieter.Monochromatic light of wavelength 506 nm wavelength is incident normally on the grating.What is the largest angle from the centerline at which an intensity maximum is formed?

Question

Quizplus · Accepted Answer

The grating equation is d*sin(θ) = m*λ, where d is the distance between lines (1/710 mm), λ is the wavelength (506 nm), and m is the order of the maximum. The largest angle occurs when m is maximized, but it must satisfy sin(θ) ≤ 1. Calculating for m = 1, 2, 3, etc., the largest angle θ that satisfies the equation is approximately 46°.

An 18-Mm-Wide Grating Has Rulings of 710 Lines Per Millimieter