The frequency comb is tiny compared to current traditional frequency combs that can be as large as a refrigerator. This tool that increases the potential applications of lasers by converting a single wavelength into multiple wavelengths, effectively creating tens to hundreds of lasers from a single laser. It would find applications in heatlhcare, IoT, mobile networks, cryptocurrencies and protecting thousands of miles of fiber optic cables under the oceans at risk of being hacked,
The small frequency comb was made possible by researchers Andrea M. Armani, Xiaoqin Shen, Rigoberto Castro Beltran, Vinh M. Diep, and Soheil Soltani – using a fundamentally different approach to invent a new method to create a frequency comb where current state-of-the-art materials such as silicon are replaced with carbon-based or organic molecules. Attaching only a single layer of a 25-atom organic molecule to the surface of a laser, frequency combs were demonstrated with 1000x reduction in power, making them ideal for mobile applications.
Professor Armani, the Ray Irani Chair in Engineering and Material Sciences at the USC Viterbi School of Engineering, likens the change from conventional silicon to organic materials as analogous to the change of "gas to electric." At the most basic level, the process that enables the comb to be generated is distinctly different in the two material classes.
"Organic optical materials have already transformed the electronics industry, leading to lighter, lower power TVs and cellphone displays, but previous attempts to directly interface these materials with lasers stumbled," said Armani, "We solved the interface challenge. Because our approach can be applied to a wide range of organic materials and laser types, the future possibilities are very exciting."