| In this Masters thesis, continuous wave fiber Raman lasers are studied. First, the resolution of the equations governing the behavior of Raman lasers with linear cavities is done through numerical simulations. An approximate analytical solution is also found and compared to the numerical solutions: the difference is around 1%. The analytical solution is used to find the optimal output power, efficiency and threshold power. Scaling rules are also obtained from this solution. A specific optimisation of the laser characteristics can be applied to numerous lasers through these rules.; The transient regime of the Raman lasers with linear cavities is explored numerically. During the transient regime, pulses of a few microseconds duration are observed in the cavity. Those pulses can reach tens of watts of peak power. The steady-state regime is reached after 40 roundtrips for a 6 stages cascade.; The stability of a fiber Raman ring laser is calculated. The analysis yields the frequencies and gain of the perturbations and whether this perturbations can self-start the laser. The Raman gain cannot self-start the laser; however the Raman effect causes power variations in the cavity. Those power variations creates perturbations and are calculated for the first time at our knowledge. The perturbations thus created can self-start the laser but since their spectral width is only a few tens of picometers, they are unlikely to be observed experimentally. The method used to do the stability analysis is part analytical, part numerical and can be used to study different all-fiber optical components. |
