Coherent beam combining of phased fiber laser array with pointing error correction using light intensity gradient...

Area of Science:

• Optics and Photonics
• Laser Technology
• Array Systems

Background:

• Coherent beam combining in multi-aperture arrays is crucial for high-power lasers.
• Large pointing errors pose a significant challenge to achieving effective beam combining.
• Existing methods may struggle with substantial pointing inaccuracies.

Purpose of the Study:

• To propose and validate a new control strategy for coherent beam combining in the presence of large pointing errors.
• To address the limitations of current techniques in handling significant beam deviations.
• To enhance the performance and applicability of phased fiber laser arrays.

Main Methods:

• A control strategy utilizing a light intensity gradient trap is introduced.
• Light intensity information is preprocessed to filter out pointing errors.
• Simulations employed the stochastic parallel gradient descent algorithm for error correction.
• Experimental verification involved an adaptive fiber-optics collimator array and a silicon-based optical chip.

Main Results:

• Successful pointing error correction for six incoherent and coherent beams was demonstrated through simulation.
• Coherent beam combining of six beams with pointing errors was achieved experimentally.
• The light intensity gradient trap method proved feasible for pointing error correction both theoretically and experimentally.

Conclusions:

• The proposed light intensity gradient trap strategy effectively corrects large pointing errors in multi-aperture systems.
• This technique offers a viable solution for achieving coherent beam combining in challenging conditions.
• The findings provide valuable technical support for the advancement of phased fiber laser arrays.