Optical Fiber Communications 4th Edition by Gerd Keiser

Exercise 13

Consider a quantum-noise-limited analog optical fiber system that uses a pin photodiode with a responsivity of 0.85 at 1310 nm. Assume the system uses a modulation index of 0.6 and operates in a 40-MHz bandwidth. If we neglect detector dark current, what is the signal-to-noise ratio when the incident optical power at the receiver is -15 dBm