Hybrid-order Poincaré sphere beam fiber laser

Area of Science:

• Optics and Photonics
• Laser Physics
• Structured Light Generation

Background:

• Vector vortex beams are crucial for advanced optical applications.
• Controlling polarization evolution in laser cavities is challenging.
• The hybrid-order Poincaré sphere (HyOPS) offers a framework for complex polarization states.

Purpose of the Study:

• To demonstrate a fiber laser directly generating vector vortex beams on the HyOPS.
• To achieve arbitrary polarization evolution within the laser cavity.
• To establish a compact and integrated source for full-state HyOPS beams.

Main Methods:

• Utilized Pancharatnam-Berry phase modulation in a fiber laser's spatial loop.
• Implemented an intra-cavity approach for direct HyOPS beam generation.
• Achieved both continuous wave and mode-locked operations.

Main Results:

• Successfully generated vector vortex beams directly within the fiber laser cavity.
• Demonstrated polarization evolution at arbitrary positions on the HyOPS.
• Achieved mode-locked operation with a pulse width of 128 ps, repetition frequency of 13.74 MHz, center wavelength of 1039.84 nm, and 3 dB bandwidth of 2.3 nm.

Conclusions:

• The developed HyOPS beam fiber laser provides a compact and integrated solution for generating full-state HyOPS beams.
• This work presents a new strategy for source-level design of complex structured light.
• The findings offer valuable insights for direct HyOPS beam generation.