All-fiber polarization beam splitting and rotating based on vector-mode-assisted coupling.

Area of Science:

• Photonics
• Optical Engineering
• Fiber Optics

Background:

• Precise control of light polarization is crucial for optical signal processing.
• Existing methods for polarization manipulation in fiber optics can be complex or limited.

Purpose of the Study:

• To propose and design a new all-fiber polarization beam splitter and rotator (PBS and PBR).
• To achieve flexible and arbitrary polarization state manipulation in fiber-guided modes.

Main Methods:

• Utilizing a three-core coupling structure with an embedded high-contrast-index ring-core.
• Employing vector-mode-assisted coupling, specifically TM₀₁, TE₀₁, and HE₂₁ modes.
• Conducting numerical simulations to analyze performance.

Main Results:

• Demonstrated effective polarization splitting and rotating capabilities.
• Achieved arbitrary angle polarization rotation by adjusting the three-core layout.
• Showcased full-dimensional SOP rotation for arbitrary polarization input via HE₂₁-assisted coupling.
• Numerical simulations confirmed favorable polarization extinction ratio and rotating purity.

Conclusions:

• The proposed vector-mode-assisted coupling enables effective management of the state of polarization (SOP) in fiber-guided modes.
• This technology holds potential for applications in polarization-based optical signal processing, multiplexing, and sensing systems.