New Laser Technology Could Help Increase Internet Speed
27 February 2014
These days the Internet allows users to download, stream content and communicate at speeds not seen before. But researchers from the California Institute of Technology (Caltech) are working on new technology that could improve the pace of data transmission in the optical fiber network even further by utilizing the potential of light.
The research group has developed a new laser based on a method called coherent phase communication, which impresses data on laser beams without the need to turn the laser on and off. The novel technique allows the data to reside in small delays in the arrival time of the waves.
Similarly to the existing laser technique known as distributed-feedback semiconductor (S-DFB), which continues to power today's worldwide optical-fiber network, the new method converts current to light using III-V semiconductor material, but it stores the light in a layer of near-absorption-free silicon. Thanks to the spatial patterning of the layer, the silicon serves as a light concentrator, bringing the newly generated light away from the light-absorbing material and into the silicon. And while the S-DFB laser's spectral purity is extremely high, it is no longer sufficient to meet the increasing demand for bandwidth. This limitation could be overcome thanks to the researchers' work, as the new laser has the capacity to deliver spectral purity with a 20 times narrower range of frequencies than is possible with the S-DFB.
The research has been published in the journal Proceedings of the National Academy of Sciences.