An unpolarized light is incident on the plane interface of air-dielectric medium shown in figure. If the incident angle is equal to Brewster angle, identify the expression representing reflected wave.

Step-by-step solution

From the given figure, the incident light rays lie in the xz -plane. Therefore, the plane of incidence is the xz -plane. The incident wave travels from the air ( z 0 ), so it propagates in the +x and +z directions. The reflected wave will travel back into the air, meaning it propagates in the +x and -z directions. The wave vector for the reflected wave can be written as k _r = k_x i - k_z k . The phase of the reflected wave is given by k _r r - t = k_x x - k_z z - t . This phase matches the expression in option (1)