US Patent 11960121 Optical connection structure

An embodiment optical body is provided in a propagation path of light between a Si waveguide and an optical fiber. The optical body changes a course of some of radiation mode light, which is emitted from the Si waveguide and propagates in a direction away from an optical axis thereof, to obtain waveguide mode light passing through itself. Thus, the amount of waveguide mode light incident on the optical fiber increases, and the coupling efficiency between the Si waveguide and the optical fiber is improved.