Bell Labs scientists have set a new optical transmission record of 15.5 Terabits per second over 7,000 kilometers, using 155 lasers, each operating at a different frequency and carrying 100 Gigabits/second of data.

The researchers also increased capacity by interfacing advanced digital signal processors with coherent detection, a new technology that makes it possible to effectively increase capacity by increasing the number of light sources introduced into a single fiber yet still separate the light into its constituent colors when it reached its destination.