Phase locking of lasers with Gaussian coupling.

Area of Science:

• Optics and Photonics
• Laser Physics
• Array Optics

Background:

• Laser arrays offer enhanced power but achieving stable in-phase locking across diverse geometries is challenging.
• Existing methods struggle with scalability and robustness against factors like array size, position, and orientation.
• Controlling phase relationships in multi-laser systems is critical for applications requiring high power density.

Purpose of the Study:

• To present a unique and robust method for achieving steady in-phase locking in laser arrays.
• To demonstrate the effectiveness of the proposed technique across various array configurations and conditions.
• To improve the beam quality and power density of laser array outputs.

Main Methods:

• Insertion of an intra-cavity Gaussian aperture in the far-field plane of the laser array.
• Experimental validation with an array of 90 lasers exhibiting sharp, high power density far-field spots.
• Testing under conditions including near-degenerate solutions and geometric frustration.

Main Results:

• Achieved steady in-phase locking for 90 lasers irrespective of array geometry, position, orientation, period, or size.
• Demonstrated robustness against challenging conditions like geometric frustration and superimposed longitudinal modes.
• Successfully suppressed internal phase structures, yielding pure Gaussian mode outputs with uniform phase and high beam quality.

Conclusions:

• The intra-cavity Gaussian aperture provides a universal solution for in-phase locking in laser arrays.
• This technique significantly enhances laser array performance, enabling focused high power density spots.
• The method holds promise for numerous applications in laser technology and scientific research.