Provided is a device for measuring at least one dimension of an object. The device includes at least one body configured to be arranged along, or around, the object. The, or each, body carries an elongate stretchable waveguide and is configured to allow stretching the waveguide along its length when arranged along, or around, the object. The, or each, waveguide is associated with a sensor. The, or each, sensor includes a light emitter arranged and operable to emit at least one light pulse through the associated waveguide, and a light detector arranged to receive the at least one light pulse conveyed through the waveguide. The device also includes a communication module communicatively coupled with the, or each, sensor, and configured to communicate measurement data from the, or each, sensor to a processor to allow determining the at least one dimension. Systems and methods for measuring at least one dimension of an object are also disclosed.

The present disclosure relates to a process by which an optical fiber is terminated with a ferrule to form an optical fiber connector assembly. The ferrule is heated at a heating temperature whereby the ferrule bore (and ferrule microhole) expands. The optical fiber is then inserted into the ferrule microhole. The ferrule then contracts when heat is no longer applied resulting in an interference fit between the optical fiber and the ferrule microhole based on the dimensions of the optical fiber and the ferrule microhole. The interference fit yields certain optical fiber characteristics within the optical fiber connector assembly. The present disclosure also relates to an optical fiber having an outer cladding comprising titania-doped silica and the resulting optical fiber characteristics.

A passive microscopic Fabry-Pérot Interferometer (FPI) sensor includes a three-dimensional microscopic optical structure formed on a cleaved tip of the optical fighter using a two-photon polymerization process on a photosensitive polymer by a three-dimensional micromachining device. The three-dimensional microscopic optical structure having a hinged optical layer pivotally connected to a distal portion of a suspended structure. A reflective layer is deposited on a mirror surface of the hinged optical layer while in an open position. The hinged optical layer is subsequently positioned in the closed position to align the mirror surface to at least partially reflect a light signal back through the optical fiber.

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 spatial light modulator (SLM) is provided that includes an optical resonator (i.e., pixel) having nanoscale size. The optical resonator having nanoscale size includes a phase-change material such as, for example, a GeSbTe alloy, sandwiched between silicon nitride cladding layers. The phase-change material can undergo a crystalline-to-amorphous phase transition which is characterized by a large change in optical properties of the resonator.

The optical fibers disclosed is a single mode optical fiber comprising a core region and a cladding region surrounding and directly adjacent to the core region. The core region can have a radius r.sub.1 in a range from 3 μm to 7 μm and a relative refractive index profile Δ.sub.1 having a maximum relative refractive index Δ.sub.1max in the range from 0.25% to 0.50%. The cladding region can include a first outer cladding region and a second outer cladding region surrounding and directly adjacent to the first outer cladding region. The first outer cladding region can have a radius r.sub.4a. The second outer cladding region can have a radius rob less than or equal to 45 μm and comprising silica based glass doped with titania.

A disclosed multimode optical fiber comprises a core and a cladding surrounding the core. The core has an outer radius r.sub.1 in between 20 μm and 30 μm. The cladding includes a first outer cladding region having an outer radius r.sub.4a and a second outer cladding region having an outer radius r.sub.4b less than or equal to 45 μm. The second outer cladding region comprises silica-based glass doped with titania. The optical fiber further includes a primary coating with an outer radius r.sub.5 less than or equal to 80 μm, and a thickness (r.sub.5−r.sub.4) less than or equal to 30 μm. The optical fiber further includes a secondary coating with an outer radius r.sub.6 less than or equal to 100 μm. The secondary coating has a thickness (r.sub.6−r.sub.5) less than or equal to 30 μm, and a normalized puncture load greater than 3.6×10.sup.−3 g/micron.sup.2.

A method for manufacturing an optical fiber includes: heating an optical fiber preform to draw glass fiber; measuring an outer diameter of the glass fiber to obtain a function of time; transforming the function of time into a function of frequency; identifying a first peak caused by a first drawing condition and a second peak caused by a second drawing condition in the function of frequency; and adjusting the second drawing condition so as to satisfy fn<fm−wm/2 or fn>fm+wm/2, where fm is a frequency of the first peak, wm is a full width at half maximum of the first peak, and fn is a frequency of the second peak.

An optical-fiber ribbon having excellent flexibility, strength, and robustness includes optical fibers having a sacrificial, outer release layer that facilitates separation of an optical fiber from the optical-fiber ribbon without damaging the optical fiber's glass core, glass cladding, primary coating, secondary coating, and ink layer, if present.

A spot size converter includes a first waveguide including a first core layer, the first waveguide propagating light; and a second waveguide including a second core layer and provided on the first waveguide, the second waveguide propagating light. The first waveguide and the second waveguide extend in a waveguide direction. A first region and a second region are provided continuously along the waveguide direction. In the first region, the second waveguide has a tapered shape in a cross section which becomes narrower as going up away from the first waveguide. An angle between a side surface of the second waveguide and a bottom surface of the second waveguide is 60° or less.