Communication over fiber using light has been in use in telecommunications for the past couple of decade due to its ability to carry large amounts of data at extremely fast speeds. In silicon, it is still in the experimental stage, but it has gotten a lot more interest in the past few years. Thermal issues are becoming more acute with RC delay, and one possible solution is photonics.
The challenge, at least so far, involves conversion of electrical signals into optical signals, and then back again. While heat isn't a factor with light, the time and energy necessary to convert those signals is less efficient over extremely short distances than using conventional digital processing. Inside a data center, where data has to be moved back and forth across wider distances, the benefits are more apparent.
The ultimate goal in this field is to develop photonic processors and storage. At this point it remains a research project.