An international team of scientists has built what they say is the world’s smallest semiconductor laser, a breakthrough in photonic technology with possible applications ranging from computing to medicine, the University of Texas at Austin’s news site reported recently.
Established semiconductor technology uses metal-oxide transistor gates to effect computational functions via the movement of electrons. Nanolasers like the one developed by physicists from the U.S., Taiwan, and China are used in the emerging field of optical computing, which uses the movement of photons instead of electrons to perform computational logic.
Photonic technology, like quantum computing, is considered a possible future replacement for existing silicon-based transistors as scaling computer chip circuitry to smaller and smaller sizes begins to push against atomic boundaries and quantum effects.
Theoretically, computing could be done with light-based transistors rather than metal ones, but scientists have run up against obstacles like the “3D diffraction limit,” a barrier that Photonics describes as “limit[ing] the ability of optical instruments to distinguish between two objects separated by a distance of less than about half the wavelength of light used to image the specimen.”
The team led by UT physics professor Chih-Kang “Ken” Shih claims to have figured out a way around that barrier.