posted by AAA .
Light from a coherent monochromatic laser of wavelength λ=2.29e-4 m is incident on two slits, both of width a, separated by a distance d. The slits are placed a distance L away from a screen where L≫d and L≫a. The diffraction/interference intensity is plotted on the figure below as a function of sin(θ) (i.e. the X axis is sin(θ) where θ varies from −90∘ to +90∘).
If I know the difraction pattern (x-axix-> sin(theta); y-axix-> I/I0), how could I know the size of the slits (both are equal)?