TOKYO-- September 07, 2022 -- NTT Corporation (NTT, Head office: Chiyoda-ku Tokyo; President & CEO: Akira Shimada) has developed a digital coherent signal processing circuit and optical device that achieves the world's largest capacity of 1.2 Tbit/s per wavelength for optical transmission, which is 1.5 times faster than before. With this development, NTT tackles the challenge of achieving advanced optical transmission technology that can economically and significantly expand the capacity of existing systems while reducing the power consumption of communication devices.

The technology has also achieved the world’s highest optical signal modulation speed of 140 Giga baud and enables double the previous world record optical transmission distance of 800 Gbit/s. As a result, the capacity of optical transmission systems will increase by 12 times and the power consumption per bit will be reduced to 10% of the widely used commercial system. The improvements in the performance and power consumption of optical transmission systems should contribute to the All-Photonics Network foundational to the IOWN[1] concept.

Our digital coherent signal processing circuit combines cutting-edge coded modulation with transmission performance approaching the theoretical limit and newly developed forward error correction that can correct bit errors in large amounts of data with low power consumption. This results in flexible coded modulation that maximizes the potential of high-speed optical devices. Furthermore, by utilizing a power-efficient algorithm to equalize signal distortion in the optical fiber transmission channel and the advanced CMOS processes, we have achieved a digital signal processing of 1.2 Tbit/s per wavelength with low power consumption.

The transceiver consists of a cutting-edge digital coherent signal processing circuit and a 140-Giga baud class optical device with the world's widest-class opto-electrical response bandwidth. In our approach, by increasing the modulation speed from 100 Giga baud to 140 Giga baud, higher resistance to waveform distortion and optical amplification noise caused by transmission could be achieved. As a result, the previous record transmission distance of 800 Gbit/s signals can be extended by more than twice that of the 100 Giga baud devices.

Toward the development of IOWN, NTT aims to create an innovative network with high capacity, low latency, flexibility, and low power consumption by continuing to expand and develop end-to-end photonics technology. We will promote the creation of economical, large-capacity, low-power-consumption networks by leveraging advanced optical transmission systems based on innovative technology. We also intend to collaborate with both international and domestic partners so that our developments can be valuable and beneficial for communities worldwide. You can access the full report about this development here.