Metasurface Design Approach Achieves Unidirectional Luminescence in LEDs

Using a metasurface-based design, researchers at the University of Santa Barbara, California (UCSB) developed a way to extract more photons from LEDs and direct the light emitted from LEDs with greater precision. Their approach could be used to create more efficient and versatile LED display and lighting technologies. LEDs emit spontaneous light, in contrast to the coherent light emitted by a laser. Spontaneous emission samples all the possible ways the photon is allowed to go, so the light appears as a spray of photons traveling in all possible directions. The UCSB team wanted to find out whether the photons generated in an LED could be herded in a desired direction through nanoscale design and fabrication of the LED’s...