Development of an S-Band Lumped Raman Amplifier Module

The global demand for data traffic continues to surge due to the increased use of smartphones, cloud computing, video sharing, and generative AI. This rapid growth necessitates greater transmission capacity in medium- and long-distance optical telecommunications networks. To meet these demands, expanding the telecommunications bandwidth from the current C- and L-bands to the S- and U-bands is under consideration. However, conventional erbium-doped fiber amplifiers (EDFAs) cannot amplify light in these bands.

Leveraging 25 years of expertise in laser manufacturing and fiber technology, Furukawa Electric has developed an S-band Lumped Raman Amplifier Module. Unlike distributed Raman amplifiers, which amplify signals using the transmission fiber, lumped Raman amplifiers incorporate an internal amplification medium, enabling high gain amplification.
The new amplifier utilizes the FRL1441U series pump laser and a dual-port Raman pump as the light source, along with a high non-linear fiber (HNLF) as the amplification medium. This combination achieves a highly efficient amplification gain of at least 30dB (High Gain Type), gain flatness of 0.4dB or lower (High Power Type), and a noise figure (NF) of 4.7dB (both types). Additionally, the gain tilt control function, adjustable by ±3dB, allows users to fine-tune system performance.

The current development was conducted and achieved as part of the National Institute of Information and Communications Technology (NICT) commissioned research “Beyond 5G – Development of extended range optical node technology for realizing ultra-high speed, large volume networks” (Key Issue JPJ012368C04501) and the 2024 Function Realization and International Joint R&D Program “Innovative ICT Fund Projects for Beyond 5G/6G” (JPJ012368G60101).

Furukawa Electric will showcase the amplifier at OFC 2025 in San Francisco, California, from April 1-3, 2025, at the Lightera Booth No. 2843. Sample shipments are scheduled to begin in the second half of 2025.
For more information on OFC 2025

Development of a new pump laser for high output power, low power consumption Raman amplifiers by expanding the range of the FRL1441U Series to support the S-band and L-band

Development of a high output, low power consumption, small S-,C-,L-band dual port pump laser for Raman amplifiers

Improved the performance of the dual port pump laser for Raman amplifiers