OPTICAL CONNECTOR UNIT AND OPTICAL CONNECTION STRUCTURE

[Problem] To provide an optical connector system with which a grating coupler and a single-mode optical fiber can be optically connected with high accuracy. [Solution] An optical connector system includes: an optical path-changing device including a fiber-holding part for holding a single-mode optical fiber along a first direction, and a reflection surface for reflecting an optical signal; and a relay device to be provided on a substrate having a grating coupler for inputting/outputting an optical signal in a second direction inclined with respect to a direction perpendicular to the substrate surface. The optical path-changing device and the relay device each have an input/output surface to/from which an optical signal is to be inputted/outputted. The input/output surface of the optical path-changing device and that of the relay device are each provided with a convex lens. The single-mode optical fiber and the grating coupler are optically coupled by inputting/outputting collimated light of the optical signal between the convex lens of the optical path-changing device and that of the relay device, and changing a direction of the optical signal by the reflection surface of the optical path-changing device.