All Problems

Diffraction of Light

Problem 5.136

Light with wavelength λ=589.0nm\lambda=589.0 \mathrm{nm} falls normally on a diffraction grating with period d=2.5μm,d=2.5 \mu \mathrm{m}, comprising N=N= =10000=10000 lines. Find the angular width of the diffraction maximum of second order.

Reveal Answer
Δθ=2λ/Nd1(kλ/d)2=11\Delta \theta=2 \lambda / N d \sqrt{1-(k \lambda / d)^{2}}=11^{\prime \prime}