A reflection reduction device includes an optical fiber (104) configured for optical sensing and having an end portion. A tip portion (102) is coupled to the end portion. The tip portion includes a length dimension (d) and is index matched to the optical fiber. The tip portion is further configured to include an absorption length to absorb and scatter light within the length dimension, and a surface (S) opposite the end portion is configured to reduce back reflections.

Embodiments described herein include a waveguide combiner having an edge coated with an optically absorbent composition and a method of coating the edge of the waveguide combiner with the optically absorbent composition. The optically absorbent composition includes one or more types of nanoparticles or microparticles, at least one of one or more dyes or one or more pigments, and a polymer matrix of one or more binders. The method includes producing an optically absorbent formulation. The optically absorbent formulation includes one or more types of particles, at least one of one or more dyes or one or more pigments, one or more binders, and one or more solvents. The optically absorbent formulation is applied on an edge of a waveguide combiner using an edge blackening tool. The formulation is cured with radiation to form the optically absorbent composition.

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 Michelson interference optical fiber temperature sensor for detecting fringe contrast change is provided. It includes a light source, an optical fiber coupler connected to a first optical fiber and a second optical fiber, a coarse wavelength division multiplexer, a first photodetector, a second photodetector, a display device, and a processing circuit connected to the display device. The light source, optical fiber coupler and coarse wavelength division multiplexer are connected sequentially in that order. The coarse wavelength division multiplexer is connected to the first photodetector and the second photodetector individually. The first photodetector and the second photodetector are connected to the processing circuit. An end of the first optical fiber or the second optical fiber facing away from the optical fiber coupler is connected to a semiconductor. It has advantages of simple and fast manufacturing process, safe and reliable sensor, stable signal, low cost, high sensitivity and high precision.

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.

The present disclosure relates to semiconductor structures and, more particularly, to Waveguide absorbers and methods of manufacture are provided. The waveguide structure includes a photonics component and a spirally configured waveguide absorber coupled to a node of the photonics component which reduces optical return loss.

When routing light on photonic integrated circuit (PIC) chips optical back-reflection and scattering can be highly detrimental to the desired application. Unused ports of optical devices, such as MMI, DC, Y-junction, PD, etc. are a cause for back-reflection and scattering, whereby the scattered light could get picked up by adjacent components, e.g. photodetectors. Management of stray light on the PIC is needed to prevent the undesired coupling between various components and to reduce noise. A dump taper may be used to guide and scatter stray light away from sensitive components or fully absorb the light while maintaining very low reflection from the taper. A doped dump taper may be used to passively absorb light reaching the unused port, thereby eliminating unwanted reflection and scattering. Alternatively, an undoped taper may be used to scatter light away from sensitive components while maintaining very low back-reflection.

The present disclosure relates to semiconductor structures and, more particularly, to Waveguide absorbers and methods of manufacture are provided. The waveguide structure includes a photonics component and a spirally configured waveguide absorber coupled to a node of the photonics component which reduces optical return loss.

The present disclosure relates to optical waveguide termination devices. In some embodiments, an optical waveguide termination device is coupled to an end of an optical waveguide. The optical waveguide termination device is a tapered structure. In various embodiments, an optical absorption rate of the tapered structure is increased to enhance a termination efficiency. The optical absorption is increased by highly-doped material, multi-layer structure, different cladding, and periodic structure. The enhancement of the termination efficiency benefits size reduction of the tapered structure.

An apparatus for coupling out radiation from an optical fiber, includes a housing, and a stop having a stop opening for delimiting an output coupling angle of radiation that is coupled out of an output end of the optical fiber to a maximum output coupling angle with respect to a central axis of the stop opening, wherein the stop is arranged in the housing. The stop has a stop body made from a transparent material, the stop body has a first total internal reflection face for reflecting radiation that is coupled out of the output end of the optical fiber with greater output coupling angles than the maximum output coupling angle, and the stop body has a second total internal reflection face for reflecting radiation that propagates opposite to the radiation coupled out of the output end and is reflected back by a workpiece.