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

Abstract

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.

Recent progress in thin-disk lasers based on various Yb-doped materials

“…However, the necessary electro-optic modulators limit the repetition rate and the maximum average output power (we assume that currently available devices could work up to about 1 kW for few-ps pulses without CPA). Using a novel nonlinear amplification technique to overcome the gain bandwidth limitations in regenerative amplifiers sub-300 fs pulses with 360 µJ pulse energy could be obtained from an Yb:YAG thin-disk crystal [21].…”

Versatile and scalable pulse compression platform

“…The latter offers a superior power-scaling, it can be operated in different operational modes, such as emitting from CW regime to 100 fs pulses with repetition rate from kHz to GHz repetition rate. Achieving sub-100 fs remains a challenging task despite the implementation of ingenious schemes to overpass this limitation [1]. In turn, this limits their impact in some of the emerging industrial applications where processing of some materials such as dielectric or semiconductor require 10-100 µJ level pulses with pulse-width below 300 fs.…”

Yb:CALYO-based femtosecond chirped pulse regenerative amplifier for temporally resolved pump-probe spectroscopy

“…Despite thin-disk based regenerative amplifier systems demonstrate high average power, it should be noted that pulse duration of such systems is not less than 700 fs. 295 fs pulses were demonstrated for thin disk RA system that applied nonlinear pulse amplification regime but with substantially reduced output power (36 W) [6]. Another approach to implementation of RA systems is based on bulk regenerative amplifiers.…”