FLUCTUATIONS IN COHERENT PULSE-PROPAGATION

Fluctuations in the coherent propagation of a pulse in a nonlinear swept-gain amplifier have been studied theoretically and compared with those occurring in the case of mode-locking by synchronous pumping. While previous authors have initiated the process by applying small random tipping angles to the Bloch vector, we have obtained similar results by using a simple semiclassical model of spontaneous emission. We demonstrate that the fluctuations can in principle be eliminated by a self-stabilisation procedure demonstrated recently in synchronously pumped dye lasers.