Phase locking of CO(2) lasers by the use of diffraction effects

Area of Science:

• Optics and Photonics
• Laser Physics
• Quantum Electronics

Background:

• Phase locking spatially separated laser resonators is crucial for high-power laser applications.
• Traditional methods often involve complex optical arrangements.
• Investigating reflective optics offers a simpler approach for high-power systems.

Purpose of the Study:

• To investigate a technique for phase locking carbon dioxide (CO(2)) lasers with spatially separated active media.
• To explore the use of solely reflective optics for phase locking applications.
• To establish phase locking conditions and analyze their impact on laser performance.

Main Methods:

• Utilized a system with two resonator branches coupled via a path allowing near-field beam propagation.
• Employed reflective optics, excluding the output coupler, for resonator construction.
• Implemented a piezoelectric translator for precise resonator length control and a fast detector for monitoring interference patterns.

Main Results:

• Achieved phase locking by managing diffraction effects and energy exchange between coupled resonators.
• Attained a maximum coupling coefficient of 2.6%.
• Demonstrated stable phase locking up to a resonator length mismatch of λ/130, validated by computer simulations.

Conclusions:

• The developed technique effectively phase locks CO(2) lasers using reflective optics.
• Diffraction effects play a critical role in establishing phase-locked operation.
• The findings align with theoretical predictions, showing excellent agreement between experimental measurements and numerical simulations.