Silicon photonic two-dimensional optical phased array.
(A) Schematic illustration of a two-dimensional emitter array. Laser light is coupled into the input waveguide on the chip and distributed equally over the array. Grating couplers act as emitters by coupling the laser light out of plane. A scanning-electron microscope picture of the array is shown in (B) and a close-up of the grating emitter is shown in (C). Reprinted by permission from Macmillan Publishers Ltd. Nature , copyright 2013.