Low-noise-figure and high-purity 10 vortex modes amplifier based on configurable pump modes

Area of Science:

• Optical Communications
• Fiber Optics
• Photonics

Background:

• Orbital Angular Momentum (OAM) multiplexing offers a promising solution for increasing optical fiber communication capacity.
• Developing efficient amplifiers for multiple OAM modes is essential for practical implementation.

Purpose of the Study:

• To investigate the performance of an all-fiber OAM amplifier for 10 vortex modes.
• To evaluate the impact of different OAM pump modes on amplification characteristics.
• To assess the potential of the amplifier for long-distance Mode Division Multiplexing (MDM).

Main Methods:

• An all-fiber amplification system utilizing few-mode erbium-doped fiber (FM-EDF) was designed.
• Mode selective components based on fused-taper mode selective couplers (MSC) were fabricated.
• Amplification experiments were conducted using OAM0, OAM1, and OAM2 pump modes.

Main Results:

• The OAM amplifier achieved mode gains (MGs) above 15 dB for 10 vortex modes with 89% purity.
• When pump and signal modes matched, MGs exceeded 20.2 dB with up to 97% purity.
• Low noise figures (NFs) below 4.9 dB, with a minimum of 3.2 dB, were recorded.

Conclusions:

• The developed OAM amplifier exhibits high-purity and low-noise characteristics in the C-band.
• Configurable pump modes allow for optimized amplification performance.
• The amplifier shows significant potential for long-distance MDM and addressing communication capacity limitations.