High spatial-density, cladding-pumped 6-mode 7-core fiber amplifier for C-band operation

Area of Science:

• Optical Engineering
• Telecommunications
• Fiber Optics

Background:

• Space division multiplexing (SDM) is crucial for increasing fiber optic communication capacity.
• Developing high-performance amplifiers for SDM systems presents challenges in managing multiple spatial channels and high pump power.

Purpose of the Study:

• To demonstrate a C-band, 6-mode, 7-core fiber amplifier for SDM transmission.
• To achieve a record number of spatial channels with high gain and low noise figure.

Main Methods:

• Utilized an all-fiberized, cladding-pumped configuration.
• Employed optimized fiber components, including a passively cooled pump laser diode, pump coupler, and pump stripper.
• Coupled high-power multimode pump light to the active fiber.

Main Results:

• Achieved amplification supporting a record 42 spatial channels.
• Obtained an average gain of 18 dB.
• Measured an average noise figure of 5.4 dB and an average differential modal gain of 3.4 dB.
• Demonstrated effective coupling of pump light without thermal degradation.

Conclusions:

• The developed amplifier is highly effective for SDM transmission.
• The design enables a significant increase in spatial channel count for optical networks.
• Optimized components ensure robust performance and high power handling.