A spatial optical interconnection system comprising:
- a semiconductor light emitting element for converting electrical signals into optical signals and for radiating the optical signals into space, the semiconductor light emitting element comprising a substrate and a plurality of surface-emitting laser diodes respectively having secondary diffraction gratings having the same pitch and radially arranged on the substrate so that the secondary diffraction gratings face a point on the substrate, wherein the laser diodes are driven with different driving currents to output respective laser light beams perpendicular to the substrate and having identical wavelengths and different phases that combine as a phase composite light beam steerable in three dimensions about the point;
- and
- a photodetector for receiving the phase composite light beam and converting the phase composite light beam to an electrical signal.