Low-crosstalk few-mode EDFAs using retro-reflection for single-mode fiber trunk lines and networks

Area of Science:

• Optical Engineering
• Telecommunications
• Photonics

Background:

• Few-mode Erbium-Doped Fiber Amplifiers (EDFAs) offer potential advantages over traditional single-mode EDFAs.
• Minimizing channel crosstalk is crucial for the performance of few-mode EDFAs in optical networks.

Purpose of the Study:

• To propose and experimentally demonstrate a low-crosstalk few-mode EDFA.
• To leverage the unique properties of symmetric photonic lanterns for improved EDFA performance.

Main Methods:

• Utilized the unitary property of the coupling matrix of a symmetric photonic lantern.
• Experimentally demonstrated a 3-channel few-mode EDFA configuration.
• Employed retro-reflection within the photonic lantern setup.

Main Results:

• Achieved small signal gain exceeding 25 dB for all three channels across the C-band.
• Maintained channel crosstalk levels below -10 dB.
• Successfully demonstrated a functional 3-channel few-mode EDFA.

Conclusions:

• The proposed few-mode EDFA design effectively suppresses channel crosstalk.
• This technology can serve as a viable replacement for multiple single-mode EDFAs in trunk lines and networks.
• The use of symmetric photonic lanterns is a promising approach for developing high-performance few-mode EDFAs.