Peak-power enhancement of a cavity-dumped cesium-vapor laser by using dual longitudinal-mode oscillations

We have performed cavity dumping of a diode-pumped alkali laser (DPAL) and have observed a saw-like structure in the pulse waveform that appears to be caused by interference between two or more longitudinal modes. We have confirmed that multimode oscillations are caused by spatial hole burning, and the largest peak was seen when only two oscillation modes were present. This phenomenon may be useful for enhancing the cavity dumping of the DPAL, but it was not always observed. Therefore, we developed a numerical simulation to predict the number of longitudinal modes excited under a given set of conditions and provides guidelines to facilitate dual-mode oscillation. Using these guidelines, we have obtained a pulse with a peak power of 250 W, which is higher than the average power circulating in the cavity and is a 38-fold enhancement of the continuous-wave (CW) output.