The present invention discloses an alignment system for calibrating a position of an optical fiber in a bore of a ferrule, comprising: an outer cylinder alignment element for calibrating a center position of an outer cylinder of the ferrule, so that the center of the outer cylinder of the ferrule is aligned with a center of the outer cylinder alignment element; a fiber core alignment element comprising a fiber core having a center aligned with the center of the outer cylinder alignment element; an optical vision system for identifying a center position of a fiber core of the optical fiber and the center position of the fiber core of the fiber core alignment element; and a controlling and moving system for actively adjusting the position of the optical fiber in the bore of the ferrule under the guide of the optical vision system.

A process of in-situ detection of hollow fiber formation includes immersing a plurality of individual glass fibers in an index-matching material. The index-matching material has a first refractive index that substantially matches a second refractive index of the glass fibers. The process also includes exposing the individual glass fibers to a light source during immersion in the index-matching material. The process further includes utilizing one or more optical components to collect optical data for the individual glass fibers during immersion in the index-matching material. The process also includes determining, based on the optical data, that a particular glass fiber of the plurality of individual glass fibers includes a hollow fiber.

Disclosed herein are methods, structures, and devices for wafer scale testing of photonic integrated circuits.

Examples disclosed herein illustrate systems and methods to determine and evaluate the quality of mechanical splices of optical fibers using insertion loss estimation. In at least some of the disclosed systems and methods, an optical fiber termination system may include a reference fiber coupling a light source and a stub fiber of a fiber optic connector, a digital camera sensor and lens to capture images of scattered light emanating from a portion of the fiber optic connector and a portion of the reference fiber both in a field of view (FOV) of the digital camera sensor, and a processor. The processor may analyze digital images of scatter light emitted from at least a portion of the fiber optic connector and the reference fiber to estimate insertion loss at the fiber optic connector.

A method for determining the refractive index profile of a preform is provided. The method involves: preparing the measured deflection angle distribution, including an extreme value determination of the deflection angle distribution, to obtain a prepared deflection angle distribution; transforming the prepared deflection angle distribution into a prepared refractive-index profile; evaluating the prepared refractive-index profile for the fixation of orientation values for the layer radius and for the layer refractive index of a hypothetical refractive index profile; generating a simulated deflection angle distribution on the basis of the hypothetical refractive-index profile with the orientation values, and transforming the deflection angle distribution into a simulated refractive-index profile; fitting the simulated refractive index profile to the prepared refractive-index profile by iterative adaptation of parameters to obtain a fitted, simulated refractive-index profile which is defined by adapted parameters, and obtaining the refractive index profile as the hypothetical refractive-index profile with the adapted parameters.

The nondestructive determination of core size of a hollow-core photonic bandgap fiber (HC-PBF) using Fabry-Perot (FP) interference is performed with an apparatus including a tunable laser source (TLS), a 12 single-mode (SM) coupler, an SM collimator, a six-axis translation stage, an optical detector, and an oscilloscope. The light from the TLS passes through the 12 SM coupler and the SM collimator to perpendicularly enter two parallel air-SiO.sub.2 interfaces of the core of the fiber and is reflected, while the TLS is tuned from one wavelength to another. Then the reflected spectrum is guided to the optical detector, where its interference intensity is converted into voltage intensity to be displayed at the oscillator and fitted with a least-squares method to obtain the distance between the two air-SiO.sub.2 interfaces. The core size of the fiber can be obtained by rotating the fiber and repeating the procedure at multiple angular positions.

Devices, systems, and methods for flexible, deployable structures with optical fiber are provided in accordance with various embodiments. For example, some embodiments include a system that may include a flexible, deployable structure and one or more optical fibers coupled with the flexible, deployable structure. In some embodiments, one or more conditions of the one or more optical fibers coupled with a flexible, deployable structure may be determined. One or more conditions of the flexible, deployable structure may be determined utilizing the determined one or more conditions of the one or more optical fibers coupled with the flexible, deployable structure. The one or more conditions of the one or more optical fibers may be correlated to the one or more conditions of the flexible, deployable structure.

An apparatus and a method for measurement of transparent cylindrical articles during their manufacture in high temperature furnaces having openings for viewing the articles as they pass through the furnace. The cylindrical articles may, for example, be optical fiber preforms which have at least two layers of vitreous material and from which optical fibers are made. Measurement is accomplished using a digital camera with a sensing and digital recording device and a lens, and a processor programmed with an algorithm which analyzes the images recorded by the sensing and digital recording device by eliminating noise, identifying and locating the outer edges of the transparent cylindrical article and calculating measurements of the article including the diameter and the axial center of the article.

A method for estimating an orientation around a central axis of an optical fiber includes radiating light from a light source toward a side surface of the optical fiber, capturing an image of the side surface of the optical fiber by receiving the light transmitted through the optical fiber at a plurality of pixels disposed along a direction intersecting the central axis of the optical fiber, generating a luminance profile for the optical fiber based on a luminance value of light received by the plurality of pixels, and estimating an orientation around the central axis of the optical fiber using the luminance profile.

Methods and apparatus for evaluating the geometric properties of optical fiber preforms, which methods include: providing an optical fiber preform having a longitudinal axis, an outer diameter and a circumference; providing a two-dimensional pattern having a length parallel to the longitudinal axis of the preform and a width greater than the outer diameter of the preform; providing an image capturing device disposed such that the preform is aligned between the pattern and the image capturing device; rotating the preform about its longitudinal axis and acquiring a first plurality of images of the pattern viewed through the preform at at least two different points along the circumference of the preform; and determining at least one geometric property of the preform from the first plurality of images.