Achieved 800mW output with a pump laser for C-band Raman amplifiers

Furukawa Electric Co., Ltd. (Head office: 2-6-4 Otemachi, Chiyoda-ku, Tokyo; President: Keiichi Kobayashi) achieved 800mW output at a low power consumption of approximately 16W with a pump laser for C-band Raman amplifiers. By applying this technology, we developed the FRL1441 Series (Fig. 1) pump laser for Raman amplifiers that has an industry leading optical output of 700mW. We started sample shipments of this pump laser in August of this year.

Directed at increasing the capacity of medium to long distance optical communication networks, which is essential to the practical implementation of 5G, technology development is progressing toward increasing the transmission speed from the current 100-400Gbs to 800Gbps and even 1.6 Tbps in the future. These faster transmission speeds require high performance Raman amplifiers to supplement OSNR (Optical Signal to Noise Ratio, ^{note 1}) degradation of the signal receiving side.
In 1989, NTT announced of the world’s first optical amplifier using a semiconductor light source (optical output of the light source was 40mW,^{note 2}). Since then, for over 20 years, Furukawa Electric has contributed to advances in optical communication as a leading manufacturer of pump lasers, a key component of Raman amplifiers. To date, we have provided a pump laser for the C-band with an industry leading optical output of 600mW, and we have continued to work to realize higher output performance.

Utilizing the InP (Indium Phosphide, ^{note 3}) semiconductor chip technology and optical module assembly technology accumulated over the years, we achieved an industry leading 800mW output with a pump laser for Raman amplifiers (Fig. 2). In this new development, we increased the efficiency by optimizing the cavity length of the semiconductor laser chip and structure of the active layer and also realized high optical coupling efficiency to the optical fiber, which is an important technology in the laser pump assembly. Utilizing this technology, we developed the FRL1441 Series pump laser for Raman amplifiers that has an industry leading optical output of 700mW and started sample shipments of this pump laser in August of this year.

This new development is expected to improve OSNR in long distance transmission following further increases to transmission speed and data volume, as well as lead to smaller Raman amplifiers and lower pump laser power consumption (by 37% compared to existing Furukawa Electric pump lasers) through a reduction to the number of pump lasers used in current systems (for example, reducing the number of pump lasers for the same wavelength from 2 to 1). Going forward, we will continue development aimed at achieving increased performance and work to commercialize a pump laser with an optical output exceeding 800mW.
The current development results will be announced on October 18 at the ISLC (International Semiconductor Laser Conference) in Matsue City, Shimane Prefecture.
As a leading company in the laser business,Furukawa Electric will continue to research, develop and commercialize high performance semiconductor laser light sources and contribute to realizing a truly prosperous and sustainable society through advancements in optical communication.