Question

A laser emits two wavelengths (λ1 = 420 nm; λ2 = 630 nm). When these two wavelengths strike a grating with 450 lines/mm, they produce maxima (in different orders) that coincide.
a. What is the order (m) of each of the two overlapping lines?
b. At what angle does this overlap occur?

Answer 1

Answer:

a) m = 3 for λ1 and m= 2 for λ2 will overlap since they have the same values

b) At what angle does this overlap occur = 34.54 degree

Explanation:

The detailed steps and appropriate formula is as shown in the attachment.