Unstable laser resonators with super-Gaussian mirrors

Area of Science:

• Optics and Photonics
• Laser Physics

Background:

• Unstable resonators are crucial for high-power lasers.
• Achieving diffraction-limited beams from unstable resonators presents design challenges.
• Tapered reflectivity mirrors offer potential solutions for beam quality control.

Purpose of the Study:

• To introduce a novel class of tapered reflectivity mirrors with a super-Gaussian profile.
• To present a geometrical-optics approach for analyzing and designing unstable resonators utilizing these mirrors.
• To experimentally validate the effectiveness of super-Gaussian mirrors in generating high-quality laser beams.

Main Methods:

• Development of tapered reflectivity mirrors with a super-Gaussian reflectivity profile (R infinity exp(-kr(n))).
• Application of a geometrical-optics framework for the analysis and design of unstable resonators incorporating these mirrors.
• Experimental testing of a super-Gaussian mirror in an unstable resonator configuration of a pulsed Nd:YAG laser.

Main Results:

• Successful fabrication of a super-Gaussian mirror using a specialized evaporation technique.
• Demonstration of the mirror's capability to generate diffraction-limited beams when integrated into an unstable resonator.
• Validation of the geometrical-optics design approach for such resonators.

Conclusions:

• Super-Gaussian mirrors represent a viable new component for unstable laser resonators.
• The developed geometrical-optics method provides an effective tool for designing resonators with these advanced mirrors.
• These mirrors significantly enhance the beam quality achievable from pulsed solid-state lasers like the Nd:YAG laser.