A new chip-based device that can shape and steer blue light could significantly reduce the size of the light projection components used in emerging applications such as VR display, autonomous vehicles, optogenetics, and even trapped-ion quantum computers. Researchers have made an optical phased array (OPA) with a wide field of view that contains no moving parts.
Phased arrays consist of multiple connected antennas that produce an electronically steerable beam of electromagnetic waves. The beam is steered by applying different phases of light at each antenna such that the output waves interfere constructively in one direction and destructively in the other. To change the beam’s direction, light is delayed in one emitter or a phase is shifted relative to another.
Such antennas have long been used to transmit radio and television signals, but in the last decade or so researchers have begun to extend the phased-array concept to visible wavelengths. Since antennas work by oscillating charges along their structure, the size of the antenna must match the resonant mode of the wavelength of the electromagnetic radiation it supports. For visible light, that means shrinking the antenna down to the nanoscale. Miniaturized VR display will lead to increased adoption of augmented and virtual reality technologies.