Optical integrated circuit comprising light path turning micro-mirror inside the optical waveguide and method of manufacturing the same

An optical integrated circuit comprising:

• a substrate;
• an optical waveguide formed by sequentially stacking a lower cladding layer, a core layer, and an upper cladding layer on a substrate;
• a groove formed by etching the upper cladding layer, the core layer, and all or parts of the lower cladding layer placed close to an end face of the optical waveguide to intercept light traveled through the core layer of the optical waveguide or to couple light into the core of the optical waveguide;
• a plurality of bonding pads spaced apart from each other on the surface of the optical waveguide around the periphery of the groove;
• a micro-mirror having at least one slanted mirror surface inclined in a range of 30° to 60° with respect to the bottom surface and cemented on the bottom of the groove to deflect horizontal light out of the core layer and/or light out of the plane of the waveguide into the core layer of the waveguide,
• a micro-mirror inserted and cemented in the groove, and having a slanted mirror surface tilted with respect to the bottom surface about 30° to 60° to turn the path of light exits horizontally from the core into the groove vertically to the substrate, or conversely, to turn the path of light vertically emitted from the upper side of the groove toward the substrate and couple the light into the core;
• and
• an active optical element which is bonded by metal bonding pads, and emits light toward the slanted mirror surface of the micro-mirror, or conversely, receives light reflected from the slanted mirror surface of the micro-mirror,
• wherein a first sidewall of the groove which faces the slanted side surface of the micro-mirror is substantially perpendicular to the substrate, and the sidewall is rotated at an angle in a range from 6° to 15° with respect to a normal cross-section of the longitudinal axis of the core layer.

A method of manufacturing an optical integrated circuit comprising a step of:

• forming optical waveguides by sequentially stacking a lower cladding layer, a core layer, and an upper cladding layer on a substrate;
• forming grooves by etching the upper cladding layer, the core layer, and all or parts of the lower cladding layer of the optical waveguides to intercept light transmitted through the core layer of the optical waveguide or to couple light into the core layer of the optical waveguide;
• cementing micro-mirrors having at least one slanted mirror surface inclined to a range of 30° to 60° with respect to the bottom surface of the micro-mirror to deflect a path of horizontal light out of the core layer, or conversely, a path of vertical light out of the plane of waveguide into the core layer of waveguide;
• and
• bonding active optical elements on bonding pads, which emit light toward the slanted mirror surface of the micro-mirror, or conversely, receive reflected light from the slanted mirror surface of the micro-mirror.