Scientists at the Columbia Engineering School have developed optical nanostructures that allow them to completely control light dispersion and engineer the refractive index.
Researchers have shown that light has the ability to propagate from one point to another without collecting any phase. Light spreads through the medium as if it is missing in space. Researchers have made zero-index and phase observations on the infrared and the chip-scale wavelength.
The research study was led by Serdar Kocaman and Chee Wei Wong. Kocaman is an electrical engineering PhD student whereas Chee Wei Wong is an associate professor in the University’s mechanical engineering department. Chee Wei Wong and Serdar Kocaman collaborated with Singapore’s Institute of Microelectronics, Brookhaven National Laboratory, and the University College of London for the research study. The study was supported by funding from the Defense Advanced Research Projects Agency and the National Science Foundation.
The researchers controlled the optical phase by combining positive and negative refractive indices. They sculptured the artificial subwavelength nanostructures to control the dispersion of light. This technique facilitated the formation of a negative refractive index in the artificial medium. The researchers then cascaded the medium, which had the negative refractive index with the medium that had a positive index.
Wong stated that the phase control of photons would enable researchers to find out techniques on how to carry data on photonic chips. He added that this technique would enable researchers to develop highly directive antennas and self-focusing light beams.