Optical Fiber Communications 4th Edition by Gerd Keiser

Exercise 26

When a preform is drawn into a fiber, the principle of conservation of mass must be satisfied under steady-state drawing conditions. Show that for a solid rod preform this is represented by the expression
where D and d are the preform and fiber diameters, and S and s are the preform feed and fiber-draw speeds, respectively. A typical drawing speed is 1.2 m/s for a 125- m outer- diameter fiber. What is the preform feed rate in cm/min for a 9-mm-diameter preform