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Parabolic-Index Ring-Core Fiber Supporting High-Purity Orbital Angular Momentum Modes
Yuanpeng Liu1, Yingning Wang1, Wenpu Geng1
1Institute of Modern Optics, Nankai University, Tianjin 300350, China.
Sensors (Basel, Switzerland)
|April 13, 2023
Summary
We developed a new graded-index ring-core fiber that enhances orbital angular momentum (OAM) mode purity by over 7%. This innovation can reduce channel crosstalk in optical communication systems.
Area of Science:
- Optical Fiber Communications
- Photonics
- Waveguide Engineering
Background:
- Spin-orbit coupling in optical fibers can lead to unwanted power transfer between modes.
- Maintaining orbital angular momentum (OAM) mode purity is crucial for advanced optical communication systems.
- Existing fiber designs struggle to effectively mitigate mode coupling and enhance OAM purity.
Purpose of the Study:
- To design and simulate a novel graded-index ring-core fiber.
- To investigate the impact of refractive index profiles on OAM mode purity.
- To enhance the purity of OAM modes for improved optical communication.
Main Methods:
- Designing a GeO2-doped silica ring-core fiber with SiO2 cladding.
- Implementing a parabolic graded-index profile in the ring core.
- Simulating the fiber performance to analyze OAM mode purity and power transfer.
Main Results:
- The parabolic-index ring-core fiber improved OAM1,1 mode purity from 86.48% to 94.43% (a 7.95% increase).
- The graded-index profile effectively inhibited spin-orbit coupling and mitigated inter-modal power transfer.
- The proposed fiber structure offers flexibility for tailoring mode order and effective mode area.
Conclusions:
- The parabolic-index ring-core fiber significantly enhances OAM mode purity.
- This fiber design shows promise for reducing channel crosstalk in mode-division multiplexed systems.
- The flexible structure allows for optimization for various optical communication applications.
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