Optical waveguide

An optical waveguide, comprising:

• a lower cladding layer;
• a patterned core layer above the lower cladding layer, the patterned core layer having peripheral surfaces;
• an upper cladding layer above the lower cladding layer, the upper cladding layer having portions disposed upon the peripheral surfaces of the patterned core layer, and the upper cladding layer formed from a resin composition that has a total light transmittance of 90% or more when cured to form a film having a thickness of 110 μm;
• and
• an upper low elasticity layer in which the portions of the upper cladding layer disposed upon the peripheral surfaces of the patterned core layer are embedded, wherein a film formed by curing a resin composition for forming the upper low elasticity layer has a tensile elastic modulus of from 1 to 2,000 MPa at 25° C.