An optical device capable of suppressing a reflected light at an end of an optical waveguide regardless of the width of the optical waveguide is provided. An optical device includes an optical waveguide and a terminator. The optical waveguide is formed on a substrate. The terminator is formed on the substrate in such a way that the terminator is connected to one end of the optical waveguide, includes a curved optical waveguide having such a curvature that it causes a bending loss in an input light input from the optical waveguide, the input light decaying as it propagates through the curved optical waveguide.

Embodiments of the invention include a method of initiating an optical fiber. In some embodiments, a distal portion of the optical fiber is coated with an energy absorbing material. In some embodiments, the material includes a metal flakes or powder dispersed in a solution of organic solvents. After the material dries, laser energy is fired through the optical fiber. The laser energy can be absorbed in the material and ignites the organic solvents. This combustion melts the material of the optical fiber, and impregnates the optical fiber with the metal flakes or powder of the material. The resulting optical fiber is thus permanently modified so that the energy applied through the fiber is partially absorbed and converted to heat.

A semiconductor photodetector comprising a closed loop configured to receive light from an external source adapted to trap light within said closed loop until absorption by the semiconductor.

Embodiments of the invention include a method of initiating an optical fiber of a tip assembly to form a finished tip assembly. In some embodiments, at least a portion of a distal portion of the optical fiber is coated with an energy absorbing initiating material. In some embodiments, the initiating material is an enamel material including a mixture of brass (copper and zinc) flakes or aluminum flakes in a solution of organic solvents. After the initiating material dries, a diode laser is fired through the optical fiber. The laser energy is at least partially absorbed in the initiating material and ignites the organic solvents. This combustion melts the material of the optical fiber, and impregnates the optical fiber with the metal flakes of the initiating material. The resulting initiated optical fiber is thus permanently modified so that the energy applied through the fiber is partially absorbed and converted to heat.

The present disclosure relates to semiconductor structures and, more particularly, to a waveguide structure with attenuator and methods of manufacture. The structure includes: a waveguide structure including semiconductor material; an attenuator underneath the waveguide structure; an airgap structure vertically aligned with and underneath the waveguide structure and the attenuator; and shallow trench isolation structures on sides of the waveguide structure and merging with the airgap structure.

A mounting surface defines a branching channel, the branching channel having a main channel and one or more sub-channels branching off the main channel. An optic fiber is affixed to the mounting surface, the optic fiber including a cladding layer and an interior surrounded by the cladding layer, wherein part of the optic fiber is suspended over the main channel. A clad light stripper includes one or more discontinuities in an outer surface of the cladding layer of a suspended section of the optic fiber, the one or more outer surface discontinuities to release a portion of the process light. The one or more subchannels include a first sub-channel having an ingress located to capture released light from an individual one of the one or more discontinuities and trap at least a portion thereof.

The present disclosure relates to semiconductor structures and, more particularly, to multi-mode optical waveguide structures with isolated absorbers and methods of manufacture. The structure includes: a waveguide structure including tapered segments; and at least one isolated waveguide absorber adjacent to the waveguide structure along its length.

Disclosed herein are methods, structures, apparatus and devices for the termination of unused waveguide ports in planar photonic integrated circuits with doped waveguides such that free-carrier absorption therein may advantageously absorb any undesired optical power resulting in a significant reduction of stray light and resulting reflections.

The present disclosure relates to semiconductor structures and, more particularly, to a photonic chip security structure and methods of manufacture. The structure includes an optical component and a photonic chip security structure having a vertical wall composed of light absorbing material surrounding the optical component.

A method for end-reflection reduction of an optical shape-sensing fiber is described. The includes: providing a tip portion having a length dimension (d); connecting the tip portion to an end portion of an optical fiber configured for optical shape-sensing, the tip portion being indexed matched to the optical fiber; and adjusting the absorption properties of the tip portion using back reflections as feedback to provide an absorption length for light traveling in the optical fiber to reduce the back reflections.