Microjoule mode-locked oscillators: issues of stability and noise

TL;DR

This paper systematically analyzes the stability and noise characteristics of thin-disk Yb:YAG mode-locked oscillators in both negative- and positive-dispersion regimes, revealing how dispersion scaling affects pulse energy and stability.

Contribution

First comprehensive analysis of stability and noise in thin-disk Yb:YAG oscillators across dispersion regimes, linking dispersion scaling to pulse energy and jitter.

Findings

Pulse energy scales with dispersion in NDR and PDR.

Chirped pulses in PDR can be compressed to hundreds of femtoseconds.

PDR exhibits extremely reduced timing jitter.

Abstract

In this work, for the first time to our knowledge, stability and noise of a thin-disk mode-locked Yb:YAG oscillator operating in both negative- (NDR) and positive-dispersion (PDR) regimes have been analyzed systematically within a broad range of oscillator parameters. It is found, that the scaling of output pulse energy from 7 $\mu$J up to 55 $\mu$J in the NDR requires a dispersion scaling from -0.013 ps$^{2}$ up to -0.31 ps$^{2}$ to provide the pulse stability. Simultaneously, the energy scaling from 6 $\mu$J up to 90 $\mu$J in the PDR requires a moderate dispersion scaling from 0.0023 ps$^{2}$ up to 0.011 ps$^{2}$. A chirped picosecond pulse in the PDR has a broader spectrum than that of a chirp-free soliton in the NDR. As a result, a chirped picosecond pulse can be compressed down to a few of hundreds of femtoseconds. A unique property of the PDR has been found to be an extremely reduced timing jitter. The numerical results agree with the analytical theory, when spectral properties of the PDR and the negative feedback induced by spectral filtering are taken into account.