Image generated by AI
AI Insight
This study investigates why high-power thin-disk lasers experience reduced output even when operating in single-mode with good beam quality. Researchers developed a numerical model that incorporates measured disk deformation data and demonstrates that higher-order optical aberrations, beyond simple defocus effects, reduce the overlap between the laser beam and the fundamental cavity mode. The model accurately predicts laser performance parameters including output power, beam diameter, and beam quality with errors below 3%.
Why it matters
The findings identify a fundamental limitation in scaling single-mode thin-disk lasers to higher powers, which is critical for industrial cutting, precision manufacturing, and scientific applications requiring high-power, high-quality laser beams. Understanding that aberration-induced modal losses occur before beam quality degradation provides a clear target for engineering improvements in next-generation laser systems.
Understand the Science
arXiv:2512.05771v3 Announce Type: replace
Abstract: Predicting the steady-state performance of high-power thin-disk lasers requires not only pump-signal energy transfer but also how disk deformation contributes intra-cavity mode formation. In this work, we address the output-power reduction that occurs even when the laser remains in a single-mode regime with $mathrm{M^2}$ around 1.1. We developed a numerical model in which the pump-induced inversion is initialized from a non-lasing multi-pass absorption model and then coupled to two-dimensional cavity-field propagation using measured disk optical path difference (OPD) maps. Applied to the Yb:YAG thin-disk laser, the model reproduces the residual pump fraction and predicts the signal power, beam diameter, and $mathrm{M^2}$ with errors of 3.0$%$, 1.7$%$, and 0.05, respectively. To interpret the measured OPD, the disk surface is further analyzed by Zernike decomposition, and the defocus term is converted into an equivalent radius of curvature (eROC). The eROC-based simulation provides the defocus-only reference performance that is theoretically reachable in the absence of higher-order aberrations, whereas the measured-OPD simulation reproduces the experimentally observed power reduction at high pump intensity. The comparison quantitatively shows that higher-order aberrations beyond defocus reduce the overlap with the fundamental cavity mode and limit power scaling, even before strong $mathrm{M^2}$ degradation appears. This result identifies aberration-induced modal loss as a key limitation in high-power single-mode thin-disk lasers.
Source: Analysis of multi-pass pumped thin-disk laser performance with measured disk deformation