NTT Corporation 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.
By using the proprietary developed device, the company has increased the optical signal modulation speed to the world’s highest 140 Giga baud and achieved 1.2 Tbit/s per wavelength, which is 1.5 times faster than before. Also, the developed device enables to double the optical transmission distance of 800 Gbit/s.
As a result, the capacity of optical transmission system will be increased by 12 times and the power consumption per bit will be reduced to 10% of the widely-used commercial system (100 Gbit/s per channel). The improvements in the performance and power consumption of optical transmission systems should contribute to an all-photonics network in the IOWN concept.
Comparison with existing technology. With this developed devices, the transmission capacity can be increased to 1.2 Tbit/s per wavelength, which is 12 times faster than the widely-used commercial optical transmission system (100 Gbit/s per wavelength). By expanding the transmission capacity per wavelength, the power consumption per bit can be reduced to less than 10% of the existing optical transceivers.
The maximum capacity per wavelength achieved so far in the world was 800 Gbit/s. Our developed device has increased this by 1.5 times. It may be possible to use a higher multi-level modulation format to increase the capacity per wavelength, but this limits the transmission distance. In our approach, by increasing the modulation speed from 100 Giga baud to 140 Giga baud, the degree of QAM levels can be suppressed, resulting in higher resistance to waveform distortion and optical amplification noise caused by transmission. As a result, the transmission distance of 800 Gbit/s signals can be extended by more than twice that of the 100 Giga baud devices.