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Orthogonal coding methods for increasing the number of multiplexed channels in coherent beam combining
Applied Optics
|March 26, 2014
Summary
Orthogonally coded modulations using Walsh codes significantly increase the number of channels for active coherent beam combining (CBC). This method allows combining at least 5 times more fibers without altering system benefits like turbulence compensation.
Area of Science:
- Optics and Photonics
- Optical Engineering
- Signal Processing
Background:
- Active coherent beam combining (CBC) is crucial for high-power laser systems.
- Current CBC techniques face limitations in the number of combinable channels.
Purpose of the Study:
- To introduce and evaluate orthogonally coded modulations for enhanced active CBC.
- To demonstrate the scalability of CBC systems using Walsh codes.
Main Methods:
- Development of orthogonally coded modulation schemes.
- Analytical, numerical, and experimental validation of the proposed method.
- Comparison with the standard multifrequency dithering technique.
Main Results:
- Walsh codes enable a significant increase in the number of combined channels.
- At least 5x more fibers can be combined using the same modulation frequency.
- The proposed modulation format does not negatively impact CBC system performance or benefits.
Conclusions:
- Orthogonally coded modulations offer a scalable solution for active CBC.
- This technique enhances channel capacity without compromising essential system functionalities.
- The approach is also applicable to partially coherent beam combining scenarios.
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