Discrete cylindrical vector beam generation from an array of optical fibers

Area of Science:

• Optics and Photonics
• Fiber Optics
• Beam Shaping

Background:

• Coherent combining of fiber arrays is crucial for high-power laser systems.
• Controlling the far-field intensity distribution is essential for various applications.
• Existing methods often result in on-axis intensity peaks for linearly polarized beams.

Purpose of the Study:

• To present a novel method for beam shaping of far-field intensity distributions from coherently combined fiber arrays.
• To generate an effective radially polarized vector beam, specifically a discrete cylindrical vector (DCV) beam.
• To achieve a central null in the far-field intensity distribution.

Main Methods:

• Arranging fibers uniformly on the perimeter of a circle.
• Superimposing linearly polarized beams of equal shape.
• Utilizing three or more beams with individually varying polarization vectors.
• Distributing beams appropriately in the near field.

Main Results:

• Successfully produced a discrete cylindrical vector (DCV) beam.
• Achieved a far-field intensity distribution with a central null.
• Demonstrated a significant contrast to the on-axis intensity peak observed with parallel linearly polarized beams.

Conclusions:

• The presented method enables precise control over the far-field intensity profile of coherently combined fiber arrays.
• The generation of DCV beams with a central null opens new possibilities for applications requiring specific polarization and intensity patterns.
• This technique offers an advantage over conventional methods by avoiding on-axis intensity peaks.