Thin-disk laser scaling limit due to thermal-lens induced misalignment instability

TL;DR

This paper identifies a fundamental limit in scaling thin-disk lasers caused by thermal lens effects that induce misalignment instability, and proposes design criteria and architectures to mitigate this issue.

Contribution

It introduces a simplified model for thermal-lens-induced misalignment growth and proposes resonator designs that are immune to this instability.

Findings

Thermal lens effects can cause self-driven misalignment growth in thin-disk lasers.

A criterion for designing stable laser resonators against this effect is developed.

Proposed resonator architectures are resistant to thermal-lens-induced misalignment instability.

Abstract

We present an obstacle in power scaling of thin-disk lasers related with self-driven growth of misalignment due to thermal lens effects. This self-driven growth arises from the changes of the optical phase difference at the disk caused by the excursion of the laser eigen-mode from the optical axis. We found a criterion based on a simplified model of this phenomenon which can be applied to design laser resonators insensitive to this effect. Moreover, we propose several resonator architectures which are not affected by this effect.