A method and system for measuring signal loss in a fiber optic cable. The tail ends of reference and test fiber optic cables are illuminated with a diffuse light. The head end of each of the reference and test fiber optic cables are positioned in a measurement area. A core imager captures an image of the core of each head-end while it is in the measurement area. Reference and test radiant fluxes emitted from the reference and test head-ends are determined from the respective core images. The relative signal loss of the test fiber optic cable is then determined by comparing the test radiant flux to the reference radiant flux.

A method of making an optical fiber sensor device for distributed sensing includes generating a laser beam comprising a plurality of ultrafast pulses, and focusing the laser beam into a core of an optical fiber to form a nanograting structure within the core, wherein the nanograting structure includes a plurality of spaced nanograting elements each extending substantially parallel to a longitudinal axis of optical fiber. Also, an optical fiber sensor device for distributed sensing includes an optical fiber having a longitudinal axis, a core, and a nanograting structure within the core, wherein the nanograting structure includes a plurality of spaced nanograting elements each extending substantially parallel to the longitudinal axis of the optical fiber. Also, a distributed sensing method and system and an energy production system that employs such an optical fiber sensor device.

A method for determining an index-of-refraction profile of an optical object, which has a cylindrical surface and a cylinder longitudinal axis, said method comprising the following method steps: (a) scanning the cylindrical surface of the object at a plurality of scanning locations by means of optical beams; (b) capturing, by means of an optical detector, a location-dependent intensity distribution of the optical beams deflected in the optical object; (c) determining the angles of deflection of the zero-order beams for each scanning location from the captured intensity distribution, comprising eliminating beam intensities, and (d) calculating the index-of-refraction profile of the object on the basis of the angle-of-deflection distribution, wherein method steps (a) and (b) are carried out with light beams having at least two different wavelengths.

An interferometric measurement method precisely determines parallelism and 3D position of guide pin holes and fiber holes in multi-fiber ferrules used in connectors. The parallelism and position are measured for the ferrule with inserted reference guide pins and reference fibers by scanning the ferrule from side in an interferometric system. Fiber hole deviations from designated locations on the ferrule end face and distance between the fiber holes and the guide pin holes are calculated as well.

Photonic errors in a photonic integrated circuit can be imaged using an on-chip light source integrated in a photonic layer of the circuit. The on-chip light source can generate light at wavelengths that propagates through one or more substrate layers to an image sensor sensitive to the wavelength range. The on-chip light source can be tunable and provide different power settings that can be utilized to detect different types of optical errors in the photonic integrated circuit.

Provided is a glass eccentricity measurement device which includes an irradiation unit that irradiates a side surface of a coated glass fiber obtained by coating the striated glass with light, and a light receiving unit that receives light scattered and/or refracted following irradiation of the side surface of the coated glass fiber therewith, and measures an eccentricity of the glass in the coated glass fiber by a pattern of brightness and darkness in the light received by the light receiving unit, in which three or more sets including the irradiation unit and a screen are provided around the coated glass fiber, and the sets are arranged respectively in directions having different angles on a circumference centered on the coated glass fiber.

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.

A system and method for measuring refractive index inhomogeneity between plates of a Lightguide Optical Element (LOE) uses an innovative measuring technique based on a shearing interferometric technique conventionally used to observe interference and test the collimation of light beams. Another feature of the current implementation is an innovative method for analyzing the characteristics of the generated interferogram to characterize discrepancies between adjacent plates in an LOE.

An apparatus for particle size and a distribution of a population of particle measurements, comprising: a non-monochromatic light source that emits a plurality of a non-monochromatic rays, a medium that includes a particle, wherein the medium is a liquid phase and the particle is suspended within the medium to form a particle-suspension, a droplet of the particle-suspension wherein the droplet is provided with a curved surface, and a detector that is provided with a light providing element.

Systems, methods and device provided for combining or splitting laser beams, including a plurality of optical fibers for providing laser beams, an image relay lens for each of the plurality of optical fibers, positioning a prism beam combiner or splitter after the image relay lenses for combining or splitting the laser beams. According to another aspect, the a prism beam combiner or splitter may include a flattened tip to transmit a portion of an input laser beam, a position sensitive detector to receive the transmitted portion of the input laser beam to track a beam axis motion and provide feedback alignment error signals based on the beam axis motion, and a driver to receive the feedback alignment error signals and to drive a motor or piezo actuated beam steering minor based on the feedback alignment error signals, wherein a laser bond inspection method implements the described systems and methods.