Researchers build an all-optical transistor

Both conventional computers and quantum computers could benefit from optical computing, which uses light rather than electricity to perform calculations. These largely speculative devices have the potential to perform certain types of computations exponentially faster than classical computers.

However, photons—light particles—have a natural aversion to modifying one another’s behavior, which is necessary for optical computing:In a vacuum, two photons that collide simply pass through each other.

The experimental realization of an optical switch controlled by a single photon, which enables light to control the transmission of light, is described by researchers at MIT’s Research Laboratory of Electronics, Harvard University, and the Vienna University of Technology, in the most recent issue of Science.As a result, it is the optical equivalent of a transistor, which is a crucial part of a computing circuit.