Logic gates represent the basic building blocks of computer processors. Conventional logic gates are electronic—they shuffle around electrons. Researchers are developing light-based optical logic gates to meet the data processing and transfer demands of next-gen computing. Aalto University scientists developed new optical chirality logic gates that operate about a million times faster than existing technologies, offering ultrafast processing speeds.
The logic gate is made of a material that emits lights with different circular polarization depending on the chirality of the input beams.
The approach, published in Science Advances, uses circularly polarized light as the input signal. The logic gates are made from crystalline materials sensitive to the handedness of a circularly polarized light beam. This serves as the basic building block for one type of logic gate (XNOR), and the remaining types of logic gates are built by adding filters or other optical components.
The team also demonstrated that a single device could contain all their chirality logic gates operating simultaneously in parallel, a significant advance over existing logic gates, which carry out a single logic operation simultaneously. Simultaneous parallel logic gates could be used to build complex, multifunctional logic circuits. The team demonstrated that the chirality logic gate could be controlled and configured electronically necessary for hybrid electrical/optical computing.