Show analytically that a beam (in a medium of index n1) entering a planar transparent plate (of index n2 and thickness d ), as in Fig. P.4.38,emerges parallel to its initial direction. Derive an expression for the lateral displacement (a) of the beam. Incidentally, the incoming and outgoing rays would be parallel even for a stack of plates of different material.

Show analytically that a beam (in a medium of index n1) entering a planar transparent plate (of index n2 and thickness d ), as in Fig. P.4.38,emerges parallel to its initial direction. Derive an expression for the lateral displacement (a) of the beam. Incidentally, the incoming and outgoing rays would be parallel even for a stack of plates of different material.