Institute of Innovative Research, 
Tokyo Institute of Technology.


Press Release

World’s fastest directly modulated laser exceeding 100-GHz bandwidth

Membrane laser on silicon carbide substrate achieves low power consumption

Nippon Telegraph and Telephone Corporation (NTT), in collaboration with Fumio Koyama, professor at the Laboratory for Future Interdisciplinary Research of Science and Technology, Tokyo Institute of Technology, has developed an ultra-highspeed membrane laser that uses an indium-phosphorus compound semiconductor on a silicon carbide substrate with high thermal conductivity. This laser, the world’s first directly modulated laser with a 3-dB bandwidth exceeding 100 GHz, can transmit at 256 gigabits (256 billion bits) per second over a distance of 2 km in a single-mode fiber.

Directly modulated lasers are now widely used in data center, but their modulation speed is limited, which has been a problem for further increasing in transmission capacity. These results will enable us to respond to the expected increase in traffic with a low-cost and low-power-consumption solution and will contribute to the realization of a high-capacity optical transmission infrastructure that supports NTT’s IOWN concept.

This research was reported in Nature Photonics on October 19, 2020.