Quantum-mechanical calculation of frequency and timing jitter for optical pulses in dispersive fibers with losses

The noise of spontaneous emission of a short pulse propagating in a fiber with losses is translated into frequency jitter, causing exponential growth of jitter. This is in contrast with a classical treatment in which the jitter remains constant. Absorption-induced frequency noise continuously affects timing through group-velocity dispersion, and the accumulated timing jitter is therefore always larger than when it is evaluated classically. This numerical discrepancy is demonstrated to be considerable and points to the importance of including quantum effects in estimations of noise in high-bit-rate communications.