Optical Fiber Communications 4th Edition by Gerd Keiser

Exercise 15

Light traveling in air strikes a glass plate at an angle 1 = 33°, where 1 is measured between the incoming ray and the glass surface. Upon striking the glass, part of the beam is reflected and part is refracted. If the refracted and reflected beams make an angle of 90° with each other, what is the refractive index of the glass What is the critical angle for this glass