Abstract: To provide an optical probe for OCT and a method of manufacturing the optical probe that can reduce reflected light generated at a boundary portion between an optical fiber and a lensed fiber. An optical probe for OCT includes an optical fiber that transmits irradiation light and back-scattered light and a lensed fiber that is fusion spliced to an end face of the optical fiber, that emits irradiation light toward the inside of a living body while collimating the irradiation light, and that collects and guides back-scattered light to the end face of the optical fiber. A refractive index adjusting material is added to the lensed fiber, and the refractive index adjusting material is diffused in an end part of the optical fiber.

Abstract: To provide an optical probe for OCT and a method of manufacturing the optical probe that can reduce reflected light generated at a boundary portion between an optical fiber and a lensed fiber. An optical probe for OCT includes an optical fiber that transmits irradiation light and back-scattered light and a lensed fiber that is fusion spliced to an end face of the optical fiber, that emits irradiation light toward the inside of a living body while collimating the irradiation light, and that collects and guides back-scattered light to the end face of the optical fiber. A refractive index adjusting material is added to the lensed fiber, and the refractive index adjusting material is diffused in an end part of the optical fiber.

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 OCT catheter and a method for manufacturing the OCT catheter, with which the operation time, manufacturing cost, and the risk of breakage of a spliced portion between a short-length fiber and an optical fiber contained in an interior member can be reduced, are provided. An OCT catheter includes an interior member that contains an optical fiber and that is to be inserted into a body, a metal tube that guides the interior member, and an optical connector. The optical connector includes a ferrule assembly including a short-length fiber and a ferrule fixed to one end of the short-length fiber, and is connectable to a rotary joint of an OCT system. The other end of the short-length fiber and one end of the optical fiber contained in the interior member are fusion-spliced together to form a spliced portion. The spliced portion is disposed in the metal tube.

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 fiber holder includes a holder main body and cord receiving groove. The holder main body has a fiber receiving groove and a first cord receiving groove. The fiber receiving groove receives and positions a coated optical fiber of an optical fiber cord with a cord jacket removed at the tip of the optical fiber cord. The cord receiving groove receives the cord jacket. A cord holding cover and a fiber pressing cover 13 are attached to the holder main body 6 for movement between respective open closed positions. The cord holder cover includes a second cord receiving groove that cooperates with the first cord receiving groove to form an insertion through hole having a circular cross-section that allows for insertion of the optical fiber. The fiber pressing cover presses the coated optical fiber against the holder main body with the coated optical fiber in the fiber receiving groove.

Abstract: A spliced optical cable assembly is reinforced at a spliced portion of coated optical fibers to have adequate strength. The spliced optical cable assembly includes: a pair of optical fiber cables in which high-strength fibers are aligned in the longitudinal direction around coated optical fibers. The outer circumference of the coated optical fibers being covered by sheaths. The spliced optical cable assembly further includes a connecting portion in which the pair of optical fiber cables are connected and the coated optical fibers extend from the sheaths. Glass fibers exposed from the coating of the coated optical fibers spliced to each other. The connected portion is covered and formed into an integral unit, together with the high-strength fibers exposed from the sheaths, by a reinforcing tube placed over the optical fiber cables and caused to contract so that both ends of the reinforcing tube engage the sheaths of the respective optical fiber cables.

Abstract: An optical fiber holder includes a holder main body and cord receiving groove. The holder main body has a fiber receiving groove and a first cord receiving groove. The fiber receiving groove receives and positions a coated optical fiber of an optical fiber cord with a cord jacket removed at the tip of the optical fiber cord. The cord receiving groove receives the cord jacket. A cord holding cover and a fiber pressing cover 13 are attached to the holder main body 6 for movement between respective open closed positions. The cord holder cover includes a second cord receiving groove that cooperates with the first cord receiving groove to form an insertion through hole having a circular cross-section that allows for insertion of the optical fiber. The fiber pressing cover presses the coated optical fiber against the holder main body with the coated optical fiber in the fiber receiving groove.

Abstract: A reinforcing member of optical fiber fusion-splicing portion and a reinforcing method thereof are provided, in which plural coated optical fibers can be collectively reinforced in the high density, and a heating mechanism for collective reinforcement can be configured at a low cost. A reinforcing member 12 which reinforces collectively fusion-splicing portions 12a of plural coated optical fibers 11 includes a heat-shrinkable tube 13, a rod-shaped tensile strength member 14 arranged so that a part of its surface comes into contact with an inner surface of the heat-shrinkable tube, and plural tube-shaped heat-fusible adhesive members 15 arranged in the heat-shrinkable tube and into which the fusion-splicing portions of the single-core coated optical fibers are individually inserted. All of the plural tube-shaped heat-fusible adhesive members 15 are arranged in one of space portions formed between the tensile strength body 14 and the heat-shrinkable tube.

Abstract: A spliced optical cable assembly is reinforced at a spliced portion of coated optical fibers to have adequate strength. The spliced optical cable assembly includes: a pair of optical fiber cables in which high-strength fibers are aligned in the longitudinal direction around coated optical fibers. The outer circumference of the coated optical fibers being covered by sheaths. The spliced optical cable assembly further includes a connecting portion in which the pair of optical fiber cables are connected and the coated optical fibers extend from the sheaths. Glass fibers exposed from the coating of the coated optical fibers spliced to each other. The connected portion is covered and formed into an integral unit, together with the high-strength fibers exposed from the sheaths, by a reinforcing tube placed over the optical fiber cables and caused to contract so that both ends of the reinforcing tube engage the sheaths of the respective optical fiber cables.

Abstract: An optical power monitoring apparatus according to an aspect of the present invention has an input optical waveguide, a light receiver, and an output optical waveguide. The input optical waveguide has a light entrance end and a light exit end. The input optical waveguide accepts light from the exterior through the light entrance end and outputs the light from the light exit end. The light receiver absorbs part of the light from the light exit end of the input optical waveguide and transmits the other part of the light. The output optical waveguide has a light entrance end and a light exit end. The output optical waveguide accepts the light transmitted by the light receiver, through the light entrance end, and outputs the light from the light exit end. The light receiver is provided on an optical path from the light exit end of the input optical waveguide to the light entrance end of the output optical waveguide.

Abstract: Raman amplification pumping light output from a pumping light source unit is supplied to a Raman amplification optical fiber through an optical circulator. The remaining Raman amplification pumping light is detected by a light-receiving element through an optical circulator and bandpass filter. Signal light that has reached a Raman amplifier propagates through the Raman amplification optical fiber while being Raman-amplified. A control section controls the power or spectral shape of Raman amplification pumping light output from each of N pumping light sources included in the pumping light source unit on the basis of the power of the remaining Raman amplification pumping light, which is detected by the light-receiving element. Hence, a Raman amplifier capable of easily controlling gain spectrum flattening in the signal light wavelength band can be obtained.

Abstract: An optical power monitoring apparatus according to an aspect of the present invention has an input optical waveguide, a light receiver, and an output optical waveguide. The input optical waveguide has a light entrance end and a light exit end. The input optical waveguide accepts light from the exterior through the light entrance end and outputs the light from the light exit end. The light receiver absorbs part of the light from the light exit end of the input optical waveguide and transmits the other part of the light. The output optical waveguide has a light entrance end and a light exit end. The output optical waveguide accepts the light transmitted by the light receiver, through the light entrance end, and outputs the light from the light exit end. The light receiver is provided on an optical path from the light exit end of the input optical waveguide to the light entrance end of the output optical waveguide.

Abstract: In a diffraction grating device (1), index modulations are formed along the longitudinal direction of an optical fiber (10) serving as an optical waveguide. The optical fiber (10) has a core region (11), an inner cladding region (12), and an outer cladding region (13) sequentially from the optical axis center. Index modulations are formed in both the core region (11) and the inner cladding region (12) of the optical fiber (10) in each of a plurality of regions A1 to AN (N is an integer; N?2) separated from each other along the longitudinal direction of the optical fiber (10). In the diffraction grating device (1), regions An (n=1 to N) in which index modulations are formed in both the core region (11) and the inner cladding region (12) and regions Bn (n=1 to N?1) in which no index modulations are formed alternately exist along the longitudinal direction.

Abstract: The present invention relates to a method and apparatus which make it possible to manufacture an optical waveguide type diffraction grating device achieving desired optical characteristics easily. In the present method, the optical fiber is irradiated as refractive index change inducing light outputted from a light source through a phase grating mask after passing through a shutter, an optical system, and a mirror. The mirror is moved in the direction of a z-axis to scan the irradiating position of the refractive index change inducing light on the optical fiber plural times. Every scan among the plurality of scans of the irradiating position, the phase grating mask is relatively displaced along the z-axis the direction opposite to each other from a reference relative position of the phase grating mask relative to the optical fiber.

Abstract: Raman amplification pumping light output from a pumping light source unit is supplied to a Raman amplification optical fiber through an optical circulator. The remaining Raman amplification pumping light is detected by a light-receiving element through an optical circulator and bandpass filter. Signal light that has reached a Raman amplifier propagates through the Raman amplification optical fiber while being Raman-amplified. A control section controls the power or spectral shape of Raman amplification pumping light output from each of N pumping light sources included in the pumping light source unit on the basis of the power of the remaining Raman amplification pumping light, which is detected by the light-receiving element. Hence, a Raman amplifier capable of easily controlling gain spectrum flattening in the signal light wavelength band can be obtained.

Abstract: In this diffraction grating device manufacturing method, refractive-index-change-inducing light of a wavelength that induces a change in refractive index is irradiated onto an optical waveguide, thus forming a diffraction grating through refractive index modulation along the longitudinal direction of the optical waveguide. At this time, the position of irradiation of the refractive-index-change-inducing light onto the optical waveguide is swung in a direction perpendicular to the longitudinal direction of the optical waveguide.

Abstract: Refractive index change inducing light UV outputted from a light source passes a shutter and an optical system, and then is reflected by a mirror, so as to irradiate an optical fiber by way of a phase grating mask. A diffracting action of the phase grating mask generates a (+)first-order light component and a (−)first-order light component, which interfere with each other, thereby generating interference fringes with a fringe interval &Lgr;. As the mirror moves along the z axis, an irradiation position at which the optical fiber is irradiated with the refractive index change inducing light UV by way of the phase grating mask is scanned. While moving the mirror upon irradiation with the refractive index change inducing light UV, the phase grating mask is vibrated along the z axis under the action of a piezoelectric device. The phase or period of vibration varies from scan to scan.

Abstract: Raman amplification pumping light output from a pumping light source unit is supplied to a Raman amplification optical fiber through an optical circulator. The remaining Raman amplification pumping light is detected by a light-receiving element through an optical circulator and bandpass filter. Signal light that has reached a Raman amplifier propagates through the Raman amplification optical fiber while being Raman-amplified. A control section controls the power or spectral shape of Raman amplification pumping light output from each of N pumping light sources included in the pumping light source unit on the basis of the power of the remaining Raman amplification pumping light, which is detected by the light-receiving element. Hence, a Raman amplifier capable of easily controlling gain spectrum flattening in the signal light wavelength band can be obtained.

Abstract: The present invention relates a method of easily fabricating a grating device having a desired reflection characteristic, and the like. In this fabrication method, the phase grating mask is relatively shifted along the longitudinal direction of the optical waveguide by a distance of one half of the grating period of the phase grating mask during the refractive index change inducing light is irradiated on the optical waveguide through the phase grating mask.