Optical sensor module

An optical sensor module, comprising:

• an optical waveguide unit;
• and
• a substrate unit, the optical waveguide unit and the substrate unit being coupled to each other,
• wherein the optical waveguide unit includes
• an under cladding layer,
• a linear core for an optical path provided on a surface of the under cladding layer,
• an over cladding layer covering the core, and
• a pair of left-hand and right-hand fitting portions for fitting engagement with the substrate unit, the fitting portions being provided in part of the over cladding layer lying in an appropriate position relative to a light-transmissive surface of the core,
• wherein the substrate unit includes
• a substrate,
• an optical element mounted on a predetermined portion of the substrate, and
• to-be-fitted portions for fitting engagement with the fitting portions of the optical waveguide unit, the to-be-fitted portions being provided in part of the substrate lying in an appropriate position relative to the optical element, and
• wherein the coupling between the optical waveguide unit and the substrate unit are provided in conditions where the to-be-fitted portions provided in the substrate unit are in fitting engagement with the fitting portions provided in the optical waveguide unit and where the substrate unit is bowed in a direction such that the optical element is moved toward the light-transmissive surface of the core.