Researchers at the University of Pennsylvania have made an important advance in this frontier of photonics, fashioning the first all-optical photonic switch out of cadmium sulfide nanowires. Moreover, they combined these photonic switches into a logic gate, a fundamental component of computer chips that process information.

via Penn Researchers Make First All-optical Nanowire Switch | Penn News.

The researchers were able to measure the intensity of the light coming out of the end of the second nanowire and to show that the switch could effectively represent the binary states used in logic devices.