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

Area of Science:

• Laser physics
• Optical engineering

Background:

• Thin-disk lasers are crucial for high-power applications.
• Thermal lensing effects can limit laser performance and stability.
• Misalignment in laser resonators is a significant challenge for power scaling.

Purpose of the Study:

• To identify and analyze the fundamental obstacle in power scaling of thin-disk lasers.
• To understand the mechanism of self-driven misalignment growth due to thermal lensing.
• To develop design criteria and resonator architectures for misalignment-insensitive thin-disk lasers.

Main Methods:

• Development of a simplified model to analyze thermal lens effects and optical phase differences.
• Investigation of laser eigen-mode excursion from the optical axis.
• Proposal and analysis of novel resonator architectures.

Main Results:

• A fundamental obstacle related to self-driven misalignment growth in thin-disk lasers was identified.
• The phenomenon was linked to changes in optical phase difference caused by laser eigen-mode excursion.
• A criterion for designing misalignment-insensitive laser resonators was established.
• Several resonator architectures immune to this misalignment effect were proposed.

Conclusions:

• Thermal lensing poses a significant challenge to the power scaling of thin-disk lasers.
• The proposed design criterion and resonator architectures can overcome self-driven misalignment.
• This work enables the development of more stable and powerful thin-disk laser systems.