The present invention provides an optical waveguide photosensitive resin composition containing a resin component and a photoacid generator, wherein the photoacid generator has a characteristic property (x) such that an absorption limit (OO transition energy) calculated based on the shape of an ultraviolet spectrum obtained by spectrometrically analyzing a 0.1 wt % propylene carbonate solution of the photoacid generator by means of an ultraviolet/visible spectrophotometer is 3.5 to 4.1 eV. Where an optical waveguide core layer is formed by using the inventive optical waveguide photosensitive resin composition, for example, the optical waveguide core layer has a lower loss, and is excellent in patternability and reflow resistance.

An optical-waveguide-clad composition includes a bisphenol type epoxy compound (A), and an epoxy compound (B) containing, in a molecule, at least one of a structure represented by the following formula (1) and a structure represented by the following formula (2), and having a molecular weight of 350 or higher. ##STR00001## In the formula (1), R.sub.1 and R.sub.2 each independently represent a hydrogen atom or an alkyl group, and m represents 2 to 15. ##STR00002## In the formula (2), R.sub.3 and R.sub.4 each independently represent a hydrogen atom or an alkyl group, and n represents 2 to 15.

A device that includes an optical coupler with a waveguide and waveguide index matched materials at an edge of a substrate, and a method of forming the device, is provided herein. The device comprises: a substrate having an edge, and an opening formed therein adjacent the edge; a layer of insulator on the substrate, which forms a bridge across the opening at the edge; a waveguide on the layer of insulator, the waveguide comprising a constant-width region and a tapered region terminating at the edge in a region of the opening; a first layer of optical epoxy in the opening, the optical epoxy indexed matched to the layer of insulator; and, a second layer of the optical epoxy on the tapered region, such that the optical epoxy optically contains an optical signal leaking from the waveguide in the tapered region.

The present invention provides an optical waveguide photosensitive resin composition containing a resin component and a photoacid generator, wherein the photoacid generator has a characteristic property (x) such that an absorption limit (O-O transition energy) calculated based on the shape of an ultraviolet spectrum obtained by spectrometrically analyzing a 0.1 wt % propylene carbonate solution of the photoacid generator by means of an ultraviolet/visible spectrophotometer is 3.5 to 4.1 eV. Where an optical waveguide core layer is formed by using the inventive optical waveguide photosensitive resin composition, for example, the optical waveguide core layer has a lower loss, and is excellent in patternability and reflow resistance.

Cured films for forming polymer layers useful in the manufacture of optical devices, particularly optical waveguides, and methods of forming such devices are provided.

A photonic system includes a photonic device, a first set of bulk optics components, a second set of bulk optics components, and optical fill material. The photonic device includes a semiconductor substrate, a dielectric layer, a first set of optical ports, a second set of optical ports, and one or more overflow structure between the first and second set of optical ports. The semiconductor substrate includes a top side, a bottom side, and a lateral side. The dielectric layer includes a top side, a bottom side on the top side of the semiconductor substrate, and a lateral side. The optical fill material fills a first interface between the first set of bulk optics components and the first set of optical ports. The one or more overflow structures provide one or more voids to receive optical fill material that overflows from the first interface.