An optical fiber has index of refraction n and diameter d. It is surrounded by air. Light is sent into the fiber along its axis, as shown in Figure P35.40.
(a) Find the smallest outside radius R permitted for a bend in the fiber if no light is to escape.
(b) What If? Does the result for part (a) predict reasonable behavior as d approaches zero? As n increases? As n approaches 1?
(c) Evaluate R assuming the fiber diameter is 100 2m and its index of refraction is 1.40.