It is not every day that scientists are able to produce an entirely new kind of light, but when they do the implications can be dramatic. When twisted light beams carrying orbital angular momentum were uncovered in 1992, researchers realized the potential to increase data transmission speeds over current approaches. Separately, in 2005, the Nobel prize in physics was awarded for the invention of the optical frequency comb — a device that creates a spectrum of equally spaced frequencies of non-twisted light. Such combs have become fundamental tools for metrology and atomic clocks.
Now, thanks to research from Alan Willner, professor of electrical and computer engineering at USC Viterbi and his recently graduated PhD student Zhe Zhao, we can add a new structure to this list. In a paper published in Nature Communications, the pair showed how combining twisted light and frequency combs together can produce an even more novel structure of light.
For some time, Willner’s lab, the Optical Communications Lab in the Ming Hsieh Department of Electrical Engineering, had separately researched twisted light beams and frequency combs. These two research paths were relatively separate in his lab until Zhao had a realization: What if we combined different optical frequencies and different twisted light? Combining these together resulted in something completely new.
For now, Willner, Zhao, and the rest of the research group are focused on what other unique designed light they can build from this new tool.