British researchers achieve a speed of 178Tbit / s via singlemode fiber
Researchers from University College London, in collaboration with two companies, have set a new record for data throughput rates over single-mode fiber optic cables. The British achieved a speed of 178Tbit / s.
The speed of the UCL researchers was achieved via 660 channels over a fiber optic cable with a length of 40 kilometers. The scientists were able to achieve a wavelength-division multiplexing bandwidth of 16.83THz by simultaneously deploying the optical S, C and L bands, with wavelengths from 1460nm to 1625nm. The team achieved this through a combination of amplification and geometric shaping: using patterns that make the best use of the phase, brightness and polarization of the light in the cable for signal transmission.
The researchers broke the record set by Japanese scientists at the beginning of this year. They achieved a bandwidth of 13.6THz via the S, C and L frequency bands in an experiment with fiber of 40 kilometers in length, in order to achieve a throughput speed of 150.3Tbit / s.
Both experiments involve speeds over single-mode fiber where light rays pass straight through the fiber, allowing for higher bandwidth and longer distances than multimode fiber with a larger core in which the light reflects and thus travels and scatters a greater distance. It is also possible to combine several cores within the fiber optic cable and with this bundling higher speeds over longer distances are possible. In April, for example, researchers from Japan’s National Institute of Informations & Communications Technology demonstrated a throughput of 172Tbit / s over a distance of 2040 kilometers by bundling three cores within the fiber optic cable.
The British researchers claim that the advantage of their technique is that it can be implemented in existing infrastructure by upgrading the amplifiers that are present at optical connections every 40 to 100 kilometers. The UCL Electronic & Electrical Engineering department collaborated with the companies Xtera and KDDI on the investigation. They publish their locations in IEEE Photonics Technology under the title Optical Fiber Capacity Optimization via Continuous Bandwidth Amplification and Geometric Shaping.