Patent ID: 8873906
Filing Date: 2014-10-28
Classification: B29D,G02B

Abstract:
1. An optical conversion element comprising a waveguide structure including at least both of an innermost core and a first outer core, the first outer core being outside the innermost core, wherein the waveguide structure includes the innermost core, the first outer core, lower cladding, and upper cladding, the innermost core is an inverse tapered type that has a cross-section area gradually decreasing toward a direction to which a mode field expands along a guided direction, the first outer core includes a ridge and is a forward tapered type that has a cross-section area gradually increasing toward the direction to which the mode field expands along the guided direction, thereby converting the mode field of guided light, and the innermost core is composed of a thin wire core that is disposed on the lower cladding, the first outer core includes a slab layer that buries therein the thin wire core and is disposed on the lower cladding and a ridge that is disposed on the slab layer and is positioned above the thin wire core, the upper cladding buries therein the ridge and is disposed on the slab layer, and a refractive index of material forming the thin wire core is greater than a refractive index of material forming the slab layer, a refractive index of material forming the slab layer is greater than or equal to a refractive index of material forming the ridge, and the refractive index of the material forming the ridge is greater than a refractive index of material forming the lower cladding and a refractive index of material forming the upper cladding.