Wave Optics

Interference, Diffraction, Polarization, Dispersion

Interference, diffraction, polarization, and dispersion are all wave phenomena that can be explained by considering light as a wave. The photoelectric effect requires particle nature of light to be explained.

Of the order of wavelength

Diffraction effects are most prominent when the size of the obstacle or aperture is comparable to the wavelength of light. For very large obstacles, light travels in straight lines with sharp shadows.

μ = sin((A + δₘ)/2) / sin(A/2)

At minimum deviation, the ray inside the prism is parallel to the base. Using Snell's law and geometry, we get μ = sin((A + δₘ)/2) / sin(A/2), where A is prism angle and δₘ is minimum deviation.

tan iₚ = μ

Brewster's law states that tan iₚ = μ, where iₚ is the polarizing angle and μ is the refractive index. At this angle, the reflected and refracted rays are perpendicular to each other, and reflected light is completely polarized.