Question

495 nm laser light falls on a diffraction grating and forms an interference pattern on a wall 0.98 m behind the grating. The third bright spot is 1088 mm from the central bright spot.

a) What is the spacing between the lines in the grating?

d = μm

b) How many lines per mm is this?

lines/mm =

c) If the grating were illuminated instead with a red 625 nm laser, what would be the distances to the first five bright spots from the central bright spot? If a bright spot does not form, enter DNE (does not exist)

x1 = m

x2 = m

x3 = m

x4 = m

x5 = m

Answer 1