1. It is desired that the reflectivity of light at normal incidence to the surface of a trans- parent medium be less than 5.0%. Which of the following materials in Table 21.1 are likely candidates: soda-lime glass, Pyrex glass, periclase, spinel, polystyrene, and polypropylene? Justify your selections.
2. Briefly explain how reflection losses of transparent materials are minimized by thin surface coatings.
3. The index of refraction of quartz is anisotropic. Suppose that visible light is passing from one grain to another of dif- ferent crystallographic orientation and at normal incidence to the grain boundary.
Calculate the reflectivity at the boundary if the indices of refraction for the two grains are 1.544 and 1.553 in the direction of light propagation.