Optical coupling devices and silicon photonics chips having the same

An optical coupling device, comprising:

• a first core layer including first and second waveguides;
• a clad layer covering the first waveguide;
• and
• a second core layer covering the second waveguide,
• wherein the second waveguide has a width decreasing with increasing distance from the first waveguide and a vertical thickness greater than that of the first waveguide, and
• the second core layer comprises a reflecting surface slantingly provided on a longitudinal axis of the second waveguide.

A silicon photonics chip, comprising:

• at least one optical device;
• a first waveguide connected to the optical device;
• a second waveguide extending from the first waveguide;
• a clad layer provided on the first and second waveguides;
• and
• a third waveguide interposed between the clad layer and the second waveguide to cover the second waveguide,
• the clad layer is formed of a material having a refractive index smaller than that of the first and second waveguides, and the third waveguide is formed of a material having a refractive index smaller than that of the second waveguide and greater than that of the clad layer,
• the second waveguide has a width decreasing with increasing distance from the first waveguide and a vertical thickness greater than that of the first waveguide.