Since the slits are spaced d apart the total size of the diffraction grating is aNd. D 1 N. Since AB Lsinth m and AB Lsinth where L is the grating period and th m and th are the angles of diffraction and incidence respectively relative to the surface normal the condition for constructive interference is The Grating Equation.
I need help with showing how to derive this formula for the diffraction of a laser.
The light from the diffraction grating is of width Wcostheta where theta is the angle to the normal that the nth order makes. If the incident radiation contains several wavelengths the mth-order maximum for each wavelength occurs at a specific angle. A diffraction grating is essentially a multi-slit surface. The light from the diffraction grating is of width Wcostheta where theta is the angle to the normal that the nth order makes.