A photonic crystal fiber amplifier for orbital angular momentum Raman amplification

Area of Science:

• Optics and Photonics
• Optical Communications
• Fiber Optics

Background:

• High-quality propagation and amplification of orbital angular momentum (OAM) modes are crucial for advanced optical communication systems.
• Existing methods face challenges in achieving efficient amplification and stable propagation of multiple OAM modes.

Purpose of the Study:

• To propose and investigate a novel photonic crystal fiber amplifier capable of amplifying orbital angular momentum (OAM) modes.
• To optimize the amplifier's performance through structural modification and doping material concentration adjustments.

Main Methods:

• Utilizing a photonic crystal fiber amplifier design.
• Employing finite element method simulations with COMSOL Multiphysics® (version 6.2) for systematic investigation.
• Optimizing amplifier structure and doping material concentration.

Main Results:

• The proposed amplifier supports steady propagation of 38 orbital angular momentum (OAM) modes.
• Achieved a maximum mode gain of 160.87 dB with pump light at 1450 nm and OAM signal at 1550 nm (300 mW pump power).
• Demonstrated low threshold power for all modes, not exceeding 250 mW, with significant improvement in signal gain compared to existing amplifiers.

Conclusions:

• The photonic crystal fiber amplifier offers high gain, low threshold power, and supports a large number of OAM modes.
• This technology has significant potential for long-distance stable OAM propagation and enhancing optical fiber communication capacity.