Question

A laser beam with wavelength λ = 550 nm hits a grating with n = 5500 grooves per centimeter.

Part (a) Express the grating spacing, d, in terms of n.

Part (b) Calculate the numerical value of d, in centimeters.

Part (c) Find the sin of the angle, θ₂, at which the 2nd order maximum will be observed, in terms of d and λ.

Part (d) Calculate the numerical value of θ₂ in degrees.

Answer 1

a)

Usually, grating spacing,

where is the number of groves per centimeter.

b)

  

c)

The grating expression is

where is the order of diffraction, is the wavelength, is the grating spacing and is the angle.

Thus,

d)