Noise in Optical Amplifier and Mode-Locked Lasers

摘要

This report describes the development of a simulation describing noise in mode-locked lasers, and some of the results of these simulations. The additive pulse mode-locking (APM) master equation is described and converted to a form compatible with previous work. Quantum noise and noise caused by the laser pump are described quantitatively and means of producing simulated noise are developed. The resulting quantum noise is compared to theory. Measures of laser noise and means of estimating the spectrum of a random signal are discussed. The measures of timing jitter and energy fluctuations from the simulation are found to agree well with an existing analytic model. Means for measuring random intensity noise (RIN) are developed. The spectrum of the output of a mode-locked laser simulation is analyzed using these tools. RIN over narrow frequency bands of the output is found to be well described by a randomly driven damped harmonic oscillator model. The effect of changing laser parameters was examined to identify strategies for developing low noise lasers. It was found that changes in the mode-locking parameter, cavity gain and loss bad the greatest effect.