Abstract: The present embodiment relates to a method for enabling axis alignment to realize a desired coupling state between CC-MCFs. In this method, a relative position and a relative angle for realizing a desired coupling state are determined by repeatedly performing a step of performing one or both of a relative movement and a relative rotation of a first CC-MCF and a second CC-MCF, and a step of calculating a coupling efficiency index between the first and second CC-MCFs by detecting light propagating through the first and second CC-MCFs, and comparing each of the obtained coupling efficiency indices.

Abstract: An optical amplifier is provided in which adjacent ones of a plurality of cores each containing a rare-earth element and included in an amplifying multi-core optical fiber (MCF) serve as coupled cores at an amplifying wavelength, a connecting MCF is connected to the amplifying MCF, a pump light source is connected to the connecting MCF, and the pump light source pumps the rare-earth element in the amplifying MCF through the connecting MCF.

Abstract: The present embodiment relates to a CC-MCF capable of generating sufficient mode coupling even with bending or twisting less. The CC-MCF includes two fiber parts having cores mutually directly or indirectly connected, each fiber part having a plurality of cores in which a pair of adjacent cores has a mode-coupling coefficient of 1 (1/m) or more. Each fiber part is provided with a transition section including a fiber end face and a stationary section adjacent to the transition section. In the stationary section, the MFD of each core is substantially constant in a fiber longitudinal direction, and in the transition section, the MFD of each core is continuously expanding from the stationary section to the fiber end face.

Abstract: Provided is a method for producing a multi-core optical fiber that includes a plurality of cores made of pure silica glass and exhibits a minor transmission loss. The method for producing a multi-core optical fiber according to the present invention is a method for producing a multi-core optical fiber including a plurality of cores made of pure silica glass substantially free of Ge and a cladding surrounding the plurality of cores and made of a fluorine-containing silica glass. The multi-core optical fiber is produced by drawing an optical fiber preform at a drawing tension T satisfying the relationship 0.06 g/?m2<T/S<0.4 g/?m2, wherein S is a total cross-sectional area of the plurality of cores.

Abstract: An optical probe has an optical fiber, a deflecting element, and a protective tube. The optical fiber includes a glass filament having a first diameter for transmitting light between the proximal and distal ends thereof and a resin layer for covering the filament except for the distal end thereof. The deflecting element is made of glass in a circular form having a second diameter larger than the first diameter, and it is connected with the optical fiber and has an end-face having a normal vector whose angle relative to the central axis is larger than the critical angle. The protective tube surrounds a portion of the optical fiber and the entire length of the deflecting element and is adhered to the side of a deflecting optical element, whereas the inside diameter of the part covering the optical fiber is smaller than that of the part covering the deflecting element.

Abstract: An optical probe has an optical fiber, a deflecting element, and a protective tube. The optical fiber includes a glass filament having a first diameter for transmitting light between the proximal and distal ends thereof and a resin layer for covering the filament except for the distal end thereof. The deflecting element is made of glass in a circular form having a second diameter larger than the first diameter, and it is connected with the optical fiber and has an end-face having a normal vector whose angle relative to the central axis is larger than the critical angle. The protective tube surrounds a portion of the optical fiber and the entire length of the deflecting element and is adhered to the side of a deflecting optical element, whereas the inside diameter of the part covering the optical fiber is smaller than that of the part covering the deflecting element.

Abstract: An optical measurement method that can suppress variation in detection sensitivity even if an optical probe is bent, and an optical probe suitably used for the method are provided. An optical probe 10 includes an optical fiber 11 that transmits light between a proximal end 11a and a distal end 11b, an optical connector 12 connected with the optical fiber 11 at a side of the proximal end 11a, a focusing optical system 13 and a deflecting optical system 14 optically connected with the optical fiber 11 at a side of the distal end 11b, and a support tube 15 and a jacket tube 16 surrounding the optical fiber 11 and extending along the optical fiber 11. The optical fiber 11 is twisted by a number of turns in a range from one turn/m to 50 turns per meter around an axis of the optical fiber as the center and fixed relative to the support tube 15.

Abstract: The optical measurement method comprises acquiring a spectrum of interference light produced by interference between back-reflected light from an object to be measured including a plurality of tissues and reference light; creating a two-dimensional reflectance image of the object to be measured according to the spectrum of the interference light; extracting regions occupied by the tissues and a boundary between the tissues in the reflectance image created; setting a range to be analyzed and a spatial averaging range according to the regions and boundary; averaging a concentration distribution of a component obtained in the spatial averaging range including the pixel and taking the average as a concentration of the component at the pixel, so as to calculate a concentration distribution of the component in the tissues; and classifying tissue type according to the extracted regions and concentration distribution, so as to generate a tissue classification image.

Abstract: An optical probe 10 includes an optical fiber 11, an optical connecter 12 being connected to the optical fiber 11, a focusing optical system 13 and a deflection optical system 14 each being connected to the optical fiber 11, a support tube 15 and a jacket tube 16 each surrounding the optical fiber 11 to extend along the optical fiber 11, and a buffer fluid 17 filled in the inner lumen of the jacket tube. The optical fiber 11 has a cutoff wavelength shorter than 1.53 ?m. The optical fiber 11, the focusing optical system 13, the deflection optical system 14, and the buffer fluid 17 and jacket tube 16 on an optical path coupled to a fundamental mode of the optical fiber each have the light transmittance of ?2 dB to 0 dB in a wavelength band of 1.6 ?m to 1.8 ?m.

Abstract: An optical probe includes an optical fiber that rotates around an axis of rotation and that transmits light; an optical connector that is connected to an end face of the optical fiber and that rotates together with the optical fiber; a supporting tube that surrounds the optical fiber and that rotates together with the optical fiber; a jacket tube that covers the supporting tube; an inner shell that is attached to the supporting tube, that surrounds the optical connector around the axis of rotation, and that rotates together with the optical fiber; an outer shell that is attached to the jacket tube and that surrounds the inner shell; and an elastic body that elastically deforms between the inner shell and the outer shell.

Abstract: A method for acquiring an optical tomographic image is disclosed. The method acquires the optical tomographic image based on a result of a Fourier transform of an interference light spectrum obtained by dividing light into first branched light and second branched light and causing mutual interference between reflected light and diffused reflected light. The reflected light arises at a reflecting body when the first branched light is irradiated onto the reflecting body. The diffused reflected light arises when the second branched light is irradiated onto an examination region. The acquisition method includes: acquiring a first optical tomographic image when an examination object is arranged in the examination region; acquiring a second optical tomographic image when the examination object is not arranged in the examination region; and acquiring the optical tomographic image based on a difference between the first optical tomographic image and the second optical tomographic image.

Abstract: Provided is an OCT device capable of restraining degradation of OCT image quality and cost increase of parts and generating a scan trigger signal.

Abstract: An optical analyzer performing analysis excellent in spatial resolution and in invasion depth is provided.

Abstract: Provided is an optical probe that can perform low-noise precise OCT measurement even if an object with a high scattering property is measured. The optical probe 20 includes an optical fiber 21 that transmits light between a proximal end 21a and a distal end 21b, an optical connector 22 connected with the optical fiber 21 at the proximal end 21a, a focusing optical system 23 and a deflecting optical system 24 connected with the optical fiber 21 at the distal end 11b, and a support tube 25 and a jacket tube 26 surrounding the optical fiber 21 and extending along the optical fiber 21. The optical fiber 21 includes a core region 41 having a refractive index n1, a first cladding region 42 surrounding the core region and having a refractive index n2, a trench region 43 surrounding the first cladding region and having a refractive index n3, and a second cladding region 44 surrounding the trench region and having a refractive index n4. The refractive indices have a relationship of n1>n2>n3<n4.

Abstract: An optical measurement method that can suppress variation in detection sensitivity even if an optical probe is bent, and an optical probe suitably used for the method are provided. An optical probe 10 includes an optical fiber 11 that transmits light between a proximal end 11a and a distal end 11b, an optical connector 12 connected with the optical fiber 11 at a side of the proximal end 11a, a focusing optical system 13 and a deflecting optical system 14 optically connected with the optical fiber 11 at a side of the distal end 11b, and a support tube 15 and a jacket tube 16 surrounding the optical fiber 11 and extending along the optical fiber 11. The optical fiber 11 is twisted by a number of turns in a range from one turn/m to 50 turns per meter around an axis of the optical fiber as the center and fixed relative to the support tube 15.

Abstract: The optical tomographic image acquisition apparatus is based on FD-OCT. A detection unit 50A which detects interference light includes a lens 51, a reflection type diffraction grating 52A, a deflection unit 53, a lens 54), and a light receiving unit 55. The interference light collimated by the lens 51 is divided by the reflection type diffraction grating 52A. Light of each wavelength is output in a different direction according to the wavelength, deflected by the deflection unit 53, and focused on a light receiving surface of the light receiving unit 55 by the lens 54. The optical tomographic image of the object is acquired based on a correspondence relationship between a light radiation position for the object and a deflection angle by the deflection unit 53 and on optical power distribution detected by the light receiving unit 55.

Abstract: A broadband light source that outputs broadband light with reduced peak power includes a pulsed light source, an optical fiber, a band-elimination filter, and a light echo unit. The optical fiber receives pulsed light output from the pulsed light source, expands the spectrum of the pulsed light by a nonlinear optical effect within the fiber to generate supercontinuum light, and outputs the supercontinuum light. The light echo unit has a plurality of optical paths between an input terminal and an output terminal thereof. At least one optical path in the plurality of optical paths serves as a loop optical path. The light echo unit receives, via the input terminal, the supercontinuum light output from the optical fiber and having traveled through the band-elimination filter, guides the supercontinuum light through the plurality of optical paths, and outputs the supercontinuum light guided by the plurality of optical paths from the output terminal.

Abstract: An optical line monitoring apparatus and optical line monitoring system which can measure a reflectance distribution in an optical line with a high spatial resolution in a short time are provided. An optical line monitoring apparatus 14A provided in a station 10A comprises an OCDR measurement section 15 for carrying out OCDR measurement, an OTDR measurement section 16 for carrying out OTDR measurement, an optical switch 13 for selectively connecting one of the OCDR measurement section 15 and OTDR measurement section 16 to the optical coupler 12, a control section 17, and a storage device 18. The control section 17 performs a predetermined arithmetic operation according to an OCDR measurement result acquired by causing the OCDR measurement section 15 to carry out the OCDR measurement and an OTDR measurement result acquired by causing the OTDR measurement section 16 to carry out the OTDR measurement.

Abstract: A laser processing apparatus 1 includes a processing light source 3 emitting processing light; an observation light emitting unit 4 emitting observation light; optical fibers 19 conducting light having a plurality of wavelengths generated at an electronic component 2; a detecting unit 5 detecting the light conducted by the optical fibers 19; and a control unit 31 controlling a light emitting state of the processing light emitting unit 3. The optical fibers 19 are categorized into four groups, and disposed so as to surround an optical fiber 18 conducting the processing light. The optical fibers 19 categorized into the four groups are capable of conducting the observation light to the electronic component 2 every group.

Abstract: The present invention relates to an optical fiber, wherein PMD will not significantly increase even when an external factor, such as a lateral pressure, a bending and the like, is applied to the optical fiber. The optical fiber is imparted with a twist that is an elastic torsion with stress.