Semiconductor optical device

A device comprising:

• a substrate including a first side and a second side that are opposite to each other, the first side being flat, the second side including an upper side and a lower side, the lower side protruding from the upper side to form a step;
• an optical function layer on a top of the substrate, the optical function layer including a first end face and a second end face that are opposite to each other, the first end face being flush with the first side, the second end face being flush with the upper side of the second side,
• wherein the device is configured to emit light via the first side via the optical function layer along a direction of a length of the optical function layer towards the first side and not in a direction perpendicular to the length of the optical function layer, and
• wherein the emitted light is generated based on the optical function layer oscillating the light in response to an injected current;
• a first film continuously covering the first end face and the first side;
• a second film different in reflectance from the first film, the second film continuously covering the second end face and the upper side of the second side;
• a first electrode electrically connected to a top of the optical function layer,
• wherein the first electrode is parallel to the optical function layer, and
• wherein an edge of the second film is spaced next to an edge of the first electrode;
• a second electrode electrically connected to a bottom of the optical function layer;
• and
• an insulating film continuously overlapping under the edge of the second film and under the edge of the first electrode,
• wherein the insulating film comprises a material different from the second film.

A device, comprising:

• a substrate including a first side and a second side that are opposite to each other, the second side including an upper side and a lower side, the lower side protruding from the upper side to form a step;
• an optical function layer on a top of the substrate, the optical function layer spanning from the first side to the second side,
• wherein the optical device is configured to emit light via the first side via the optical function layer along a direction of a length of the optical function layer towards the first side and not in a direction perpendicular to the length of the optical function layer, and
• wherein the emitted light is generated based on the optical function layer oscillating the light in response to an injected current;
• a first film continuously covering a first end face and the first side;
• a second film different in reflectance from the first film, the second film continuously covering a second end face and the upper side of the second side;
• and
• a first electrode electrically connected to a top of the optical function layer,
• wherein the first electrode is parallel to optical function layer, and
• wherein the second film continuously extends from the second end face to overlap under an edge of the first electrode.

A method, comprising:

• injecting current to an optical device;
• and
• emitting light via an optical function layer of the optical device, wherein the optical device comprises:
• a substrate including a first side and a second side that are opposite to each other, the second side including an upper side and a lower side, the lower side protruding from the upper side to form a step;
• the optical function layer configured to be on a top of the substrate, the optical function layer spanning from the first side to the second side,
• wherein the device is configured to emit the light via the first side via the optical function layer along a direction of a length of the optical function layer towards the first side and not in a direction perpendicular to the length of the optical function layer, and
• wherein the emitted light is generated based on the optical function layer oscillating the light in response to an injected current;
• a first film continuously covering a first end face and the first side;
• a second film different in reflectance from the first film, the second film continuously covering a second end face and the upper side of the second side;
• and
• a first electrode electrically connected to a top of the optical function layer,
• wherein the first electrode is parallel to optical function layer, and
• wherein the second film continuously extends from the second end face to overlap under an edge of the first electrode.