Optical fiber mounted photonic integrated circuit device

An optical fiber mounted photonic integrated circuit device, comprising:

• an optical integrated circuit device configured to be provided with an optical waveguide core group where a plurality of optical waveguide cores having portions that are tapered in the direction of the width within a plane are aligned on a substrate;
• and
• a single mode optical fiber having an inclined connection end surface inclined relative to the propagation of light configured to be optically coupled with the optical waveguide core group, wherein
• the optical waveguide cores are aligned parallel to each other at intervals that can allow for mutual directional coupling and that are narrower than the width of the core of the single mode optical fiber,
• the inclined connection end surface of the single mode optical fiber and the upper surface of the end portions of the optical waveguide cores face each other for coupling,
• the number of optical waveguide cores in the optical waveguide core group is seven, and
• the optical waveguide cores in the optical waveguide core group connect with a clad layer of the single mode optical fiber.