Thermo-optical model of repetitively pumped solid-state lasers

Area of Science:

• Laser Physics
• Optical Engineering
• Materials Science

Background:

• Solid-state lasers are crucial for various applications.
• Controlling the transverse mode volume (TEM00) is essential for high-quality laser beams.
• Thermo-optical effects in repetitively pumped lasers can significantly impact cavity stability and mode properties.

Purpose of the Study:

• To develop and experimentally validate a thermo-optical model for repetitively pumped solid-state lasers.
• To investigate the factors limiting the TEM00 Gaussian-mode radius within the laser rod.
• To understand the implications of this mode radius limitation on achievable laser energy extraction.

Main Methods:

• Development of a comprehensive thermo-optical model.
• Experimental verification of the model's predictions.
• Analysis of cavity mode behavior under repetitive pumping conditions.

Main Results:

• The model accurately predicts cavity stability and TEM00-mode volume.
• A maximum theoretical TEM00 Gaussian-mode radius was identified within the laser rod.
• This limitation arises from cavity mode bifocusing, even in birefringent-suppressing materials.
• Conventional optics and dual-laser-head configurations offer minimal improvement.

Conclusions:

• Thermo-optical bifocusing imposes a fundamental limit on the TEM00-mode radius in solid-state lasers.
• This limit restricts the maximum extractable TEM00-mode energy from a given laser cavity.
• The findings necessitate consideration of this effect in laser design for optimized performance.