Patent ID: 7580336

Claim:
An optical head comprising: a light transmitting element emitting a beam of light; a planar waveguide formed on a substrate and receiving the beam emitted from the light transmitting element; a beam input/output coupler having a plurality of thin films formed on a portion of the planar waveguide and stacked on each other, an optical disc formed on or above the beam input/output coupler, wherein the beam input/output coupler receives the beam from the planar waveguide and transmits the beam at an angle toward the disc, and wherein the beam input/output coupler receives the beam reflected from the disc and transmits the reflected beam into the planar waveguide; and wherein the plurality of thin films includes a leaky mode directional coupler emitting the beam propagating in the planar waveguide upward and allowing the beam reflected from the disc to be incident on the planar waveguide, and a beam splitter separating the beam emitted upward by the leaky mode directional coupler and the beam reflected from the disk. a light receiving element receiving the reflected beam transmitted into the planar waveguide through the beam input/output coupler.