Numerical and Experimental Analysis of Nonlinear Regenerative Amplifiers Overcoming the Gain Bandwidth Limitation

We present a numerical and experimental analysis of a nonlinear architecture to overcome the gain bandwidth limitation in regenerative amplifiers. This technique is based on the optimization of dispersion and nonlinear effects during the amplification process to obtain broad-bandwidth pulses that can be compressed to short durations with high temporal quality. We demonstrate the advantage of this method to maintain an excellent temporal quality of pulses even at high levels of optical nonlinearity. The technique has been applied to regenerative amplifiers using Yb:YAG, Yb:KYW, and Yb:CALGO crystals as gain media. In all cases we achieved the shortest pulse duration ever obtained from regenerative amplifiers using the respective laser crystals. These results underline the benefits of this amplification technique with respect to current state of the art.