Optical antenna

An optical antenna, comprising:

• a waveguide;
• a plurality of first dielectric structures, arranged outside both sides of the waveguide respectively, and arranged periodically and symmetrically along a light propagation direction;
• and
• a plurality of second dielectric structures, arranged on both sides above the waveguide respectively, and arranged periodically and symmetrically along the light propagation direction,
• wherein the waveguide, the plurality of first dielectric structures and the plurality of second dielectric structures are separated by a third dielectric, a periodic size of the plurality of first dielectric structures is consistent with a periodic size of the plurality of second dielectric structures, and the plurality of first dielectric structures and the plurality of second dielectric structures have a displacement offset relative to each other along the light propagation direction;
• the plurality of first dielectric structures and the plurality of second dielectric structures disturb an evanescent field around the waveguide, and generate two radiation light fields correspondingly, the two radiation light fields interfere with each other before being cancelled under the waveguide, and a radiation energy is radiated to an upper free space side.