A measurement system includes an illumination unit configured to irradiate a measurement target with illumination light, an imaging unit configured to capture an image of light reflected by or transmitted through the measurement target, an acquisition unit configured to acquire positional relationship information representing a positional relationship between the illumination unit and the measurement target and a positional relationship between the imaging unit and the measurement target, and a correction unit configured to correct a luminance of at least one of the illumination light emitted by the illumination unit and the image captured by the imaging unit based on the positional relationship information in such a way as to correct a luminance change of the measurement target image captured by the imaging unit, wherein at least two of the measurement target, the illumination unit, and the imaging unit are variable in spatial position.

Measurement system, image correction method, and computer program

PURPOSE:To facilitate the manufacture and realize low loss by separating a tapered waveguide and respective branch waveguides to a specific gap and also separating the branch waveguides to a specific gap while the axes of both the waveguides are aligned at the connection part between the expanded waveguide and branch waveguides. CONSTITUTION:While the axes of both the enlarged waveguide 32a and branch waveguides 33a and 34a are aligned with each other at the connection part between the both, the expanded waveguide 32a and branch waveguides are separated to the specific gap, and the branch waveguides are also separated to the specific gap. Therefore, a clad material is supplied sufficiently in between the waveguides, specially, nearby the branch point in a process of embedding a main waveguide 31, the expanded waveguide 32a, and the branch waveguides 33a and 34a in a clad at the time of the manufacture of the circuit. Consequently, neither pattern deformation nor a deficiency in the embedding of the waveguides is caused nearby the branch point and the low-loss circuit which is easily manufacture and has superior reproducibility is obtained.

Branching and multiplexing optical waveguide

PROBLEM TO BE SOLVED: To provide a local injection technique for causing signal light to enter an optical fiber from its lateral face. SOLUTION: This optical fiber lateral incidence device is equipped with a first fiber guide 15 for holding a first optical fiber 4 bent with a prescribed radius of curvature of 10 mm along the surface of a planar plate 18, and a second fiber guide 13 allowing a second optical fiber 14 to output signal light for coated fiber collation at a prescribed angle toward a prescribed position on a lateral face of the optical fiber 4. According to this optical fiber lateral incidence method, the signal light from the optical fiber 14 is caused to enter a lateral face of the optical fiber 4 via a refractive-index matching member 12. It is possible to geometrically and experimentally determine the prescribed radius of curvature, the prescribed position, and the prescribed angle. In an experimental manner, they can be determined by causing the signal light to be outputted to the matching member 12, the signal light propagating through the core of the optical fiber 4. COPYRIGHT: (C)2009,JPO&INPIT

Optical fiber lateral incidence method and its device

PURPOSE:To obtain a light branching device having superior working stability and capable of reducing loss. CONSTITUTION:This light branching device has a substrate 201, a 1st core member 210 formed on the substrate 201, a 2nd core member 220 formed on the substrate 201 and made thinner as the member 220 is brought close to the 1st core member 210 and a 3rd core member 221 formed on-the substrate 201 and made thinner as the member 221 is brought close to the 1st core member 210.

Light branching device and optical parts

An optical branching device includes a main waveguide and a branching waveguide. A portion of the main waveguide is bent and the branching waveguide is placed close to the bent part of the main waveguide. The branching waveguide has a taper structure such that a width of the branching waveguide is gradually decreased in a propagation direction of light. A central axis of the branching waveguide is tilted from a line extended from a straight part of the main waveguide toward the direction X, or the bending direction of the main waveguide. An input end of the branching waveguide has a normal vector tilted from the central axis of the branching waveguide toward the direction Y, an opposite direction of the bending direction of the main waveguide. With above-mentioned structures, light radiated from the bent part of the main waveguide can be launched into the input end of the branching waveguide and transmitted through the branching waveguide efficiently.

Optical branching devices

PURPOSE:To obtain branched light with excellent transmission characteristics while suppressing the mode conversion loss of transmission light by optically coupling a main line with a tap fiber without reducing the radius of curvature of a main line optical fiber too small CONSTITUTION:The main line optical fiber 1 consists of a multi-mode optical fiber having a core 3 and a clad 5 and a part of light in a waveguide mode is converted into clad mode light at a mode conversion area 8 in a bent part 1a Since a gap between the area 8 and the one end part 2a of the tap fiber 2 is filled with a light translucent material 7 having >=1 diffractive index, the clad mode light in the area 8 can be lead into the material 7 and made incident on the fiber 2 Since only a part of the waveguide mode light is converted into the clad mode light in the area 8 without converting the clad mode light up to radiation mode light and it is unnecessary to reduce the radius R of curvature of the bend part 1a too small, the mode conversion loss of the transmission light can be suppressed

Optical fiber tap

PURPOSE:To provide an inspection device capable of recognizing defects with high accuracy and being easily controlled with a simple optical system and easily detecting unevenness defects of a large area even with a size in an order of millimeters. CONSTITUTION:An inspection device for small unevenness of planar objects comprises a laser light source 2, an optical fiber 6 of a core diameter (a), a convex lens 7 having a focal distance (f) of more than 100a, a cylindrical lens 8 for causing light to impinge on the surface of a planar subject for inspection, a screen 4 on which light reflected from the surface of the subject for inspection is projected, a CCD camera 5 for taking screen images, and an image processing portion 9. The convex lens 7 is disposed at a place separate by more than the focal distance from the end of the optical fiber and the cylindrical lens 8 forms light emitted from the convex lens 7 into rough slit light and causes the rough slit light to impinge on the surface of the planar subject for inspection at an angle of incidence phi from the diagonal direction, and light reflected at the surface in accordance with the surface configuration is projected onto the screen and the image processing portion 9 recognizes defective parts from image data.

Inspection device for small unevenness of planar object

PURPOSE:To obtain a branching circuit which has a wide angle and a low loss although its constitution is simple by composing the circuit of a straight transmission line and a couple of branching transmission lines and arranging them so that the branching transmission lines face the linear transmission line closely CONSTITUTION:An end part of the straight transmission line 1 is tapered having the sectional area reduced gradually and optical transmission lines 1a and 1b are formed at mutually opposite parts The couple of branching transmission lines 2 and 2 are equal in refractive index to the straight transmission line 1 and slanting optical transmission lines 2a and 2a corresponding to the taper of the optical transmission lines 2 and 2 are provided at end parts of the branching transmission lines 1a and 1a Those straight transmission line 1 and branching transmission lines 2 and 2 are so arranged that the respective optical transmission lines 1a and 1a and 2a and 2a are close to each other, but their distance (d) is reduced as much as possible and preferably about a submultiple of the wavelength of light to be transmitted

Optical branching circuit

PURPOSE:To enhance luminance of emitted light while preventing lowering of CCD output by setting the distance between the view of a two-dimensional image input unit and an illuminator while matching with the emission pattern of the illuminator CONSTITUTION:In the view of an area type CCD camera 7 in a two-dimensional image input unit, the ratio of distances from the opposite ends of a surface to be inspected and the emission end 11 of an illuminator is set equal to or close to the ratio of intensities of light projected from the illuminator to the opposite ends of the surface to be inspected When light is projected from the illuminator through an optical fiber light guide 4 onto an inspection surface 1 from the side thereof, a point on the inspection surface 1 remote from (close to) the emission end 11 of the illuminator is irradiated with light having high (low) intensity but the light arriving at the inspection surface 1 has intensity which is lower (higher) as the point is remote (close) Such illumination light provides a shade caused by a defect on the inspection surface 1 clearly regardless of the distance Image of the inspection surface 1 is picked up by means of the camera 7 and a shade contained in the image signal is detected as a defect by an image processor 8

Surface defect inspection system

PURPOSE:To obtain a low-loss optical fiber tap circuit by making a connection through a transparent body whose refractive index is >=1. CONSTITUTION:A tap optical fiber 2 for projection is connected through the transparent body 7 whose refractive index is >=1 to the 1st bent part of a trunk line optical fiber 1 which has a core 11 and a clad 12, and a tap optical fiber 3 for incidence is connected to the 2nd bent part 14 of the trunk line optical fiber 1 similarly. Part of light power propagated in the core 11 of the trunk line optical fiber 1 leaks from the 1st bent part 13 and is guided to an optical fiber 2 through the transparent body 7. The light power of another system which is guided by the tap optical fiber 3, on the other hand, is guided from the 2nd bent part 14 to the trunk line optical fiber 1. The end surfaces of the tap optical fibers are preferably tapered linearly or along the bent parts 13 and 14.

Kagami Manabu

Papers

Optical fiber tap

Inspection device for small unevenness of planar object

Optical branching circuit

Surface defect inspection system

Optical fiber tap circuit