A method for determining a refractive index profile of an optical object having a cylindrical surface includes: (a) scanning the surface at a first plurality of scanning locations with a pinhole aperture in a path of one or more optical beams; (b) measuring a first deflection function based detecting the optical beams after deflection by the optical object for each of the first plurality of scanning locations; (c) scanning the surface at a second plurality of scanning locations where the path of the optical beams is free of the pinhole aperture; (d) measuring a second deflection function based on detecting the optical beams after deflection by the optical object for each of the second plurality of scanning locations; (e) merging at least portions of the first and second deflection functions to obtain a composite deflection function; and (f) calculating the refractive index profile using the composite deflection function.

An object of the present disclosure is to make it possible to monitor wavelengths of optical signals in an optical monitor device for a plurality of optical fibers.

The present disclosure is an optical monitor device that detects an intensity of light propagating through a plurality of optical fibers, the optical monitor device including: an optical splitting unit that splits a part of incident light from the plurality of optical fibers into a first direction and a rest into a second direction at a constant splitting ratio, and emits light; and a light receiving portion that receives emitted light in the second direction from the optical splitting unit, in which the light receiving portion includes light receiving elements larger in number than the optical fibers are two-dimensionally arranged, and a wavelength dependent portion that causes the light receiving portion to receive light at a position on a light receiving surface that varies depending on a wavelength of the emitted light, and obtains a wavelength of the emitted light on a basis of a position of the emitted light on the light receiving surface.

Methods and algorithms are described herein for identifying core elements within a multicore optical fiber using single end-face image processing and/or lateral image processing. A method includes capturing a plurality of lateral images of the multicore optical fiber at various rotational orientations, determining an average intensity of each horizontal row from each of the lateral images, and compiling the average intensity of each of the plurality of horizontal rows into a plurality of datasets, each plurality of datasets corresponding to one of the lateral images. The plurality of datasets are compounded into a compounded image, a subset of the plurality of datasets is selected from the compounded image, and an image intensity of the subset of the plurality of datasets is analyzed. Based on the analysis, at least one structural component of each of at least two core elements present within the multicore optical fiber is identified.

Examining a light optical element (LOE) may include placing a first slit optically between a projector configured to emit light and the LOE's first major surface and placing a second slit optically between the LOE's second major surface and a detector. Facet parallelism between two facets may be deduced based on a shift of the image reflected from the first facet to the second facet relative to light transmitted normal to the first and second major surfaces through a portion of the substrate not including a facet. Facet refractive index homogeneity or deviation may be deduced based on the light transmitted through the facet relative to light transmitted normal to the first and second major surfaces through a portion of the substrate not including a facet.

An inspection method for an optical fiber ribbon in which a plurality of optical fibers are arranged in parallel and intermittently coupled in a longitudinal direction by a coupling resin. The inspection method includes emitting light toward the optical fiber ribbon that travels on a roller, from a direction along a tangent line of a surface of the roller with which the optical fiber ribbon comes into contact and parallel to a direction in which the optical fiber ribbon travels, to acquire an image in which the optical fiber ribbon is projected as a shadow, based on light that passed around the optical fiber ribbon, detecting an interval between the optical fibers, based on the image, and detecting a position of the coupling resin, based on the image.