- #1

L_landau

- 27

- 0

## Homework Statement

A diffraction grating is made up of slits of width 300 nm with separation 900 nm. The grating is illuminated by monochromatic plane waves of wavelength l 600 nm at normal incidence. How many maxima are there in the full diffraction pattern?

## Homework Equations

mλ = dsinθ

## The Attempt at a Solution

I thought that I could just use the above equation and doing so I get m = 1.5. However, the solution uses

(a+b)sinθ = mλ . Can I really just add the slit width and the separation width like that?