Depolarization self-compensation in high-power lasers enabled by a mid-cavity quartz rotator

Area of Science:

• Optics and Photonics
• Laser Physics
• Materials Science

Background:

• Depolarization caused by thermal stress is a key challenge in high-average-power laser amplifiers.
• Current solutions involve complex active methods or magneto-optical effects, increasing system cost and complexity.

Purpose of the Study:

• To introduce and validate a passive polarization self-compensation technique for laser amplifiers.
• To reduce depolarization without active controls or polarizers, simplifying system design and cost.

Main Methods:

• Utilizing a quartz rotator within a relay-imaged, multi-pass amplifier.
• Developing a theoretical framework and conducting experimental validation.
• Employing a high-damage-threshold, reciprocal material.

Main Results:

• Achieved a 47× reduction in depolarized light in a 4-pass cavity.
• Demonstrated a passive, polarizer-free approach.
• Validated the theoretical framework experimentally.

Conclusions:

• The passive polarization self-compensation technique effectively mitigates depolarization in laser amplifiers.
• This method offers a simplified, cost-effective alternative to active compensation.
• The technique shows scalability for inertial fusion energy drivers and broadband lasers.