Abstract: Provided is a method of manufacturing an optical fiber base material using a MCVD method, including: a step of heating a glass tube while rotating the glass tube and supplying a gas into a through-hole of the glass tube, wherein in at least a part of the step, the inside of the through-hole is pressurized so that an outer diameter of the glass tube increases.

Abstract: Provided is a method for manufacturing an optical fiber preform using a combustion burner. The method includes at least one of: a step ? of, when a mode is changed from a deposition mode to a non-deposition mode, changing a gas discharged from a combustion gas port of the burner from a combustion gas to a purge gas, while maintaining a pilot light and a flow rate of a supporting gas from supporting gas discharge nozzles of the burner so that the nozzle tip does not glow; and a step ? of, when the mode is changed from the non-deposition mode to the deposition mode, changing a gas discharged from the combustion gas port from a purge gas to a combustion gas, while maintaining a pilot light and the flow rate of the supporting gas so that the nozzle tip does not glow.

Abstract: An optical fiber preform that is used in a method in which a core rod that forms a core is inserted into a quartz tube that forms a cladding, and at the same time as they are fiber-drawn, the quartz tube and the core rod are formed into a single body, includes: a tapered portion that is formed by grinding an outer circumferential portion of a distal end portion of the quartz tube into a tapered shape; and a conical portion that is formed by welding a dummy tube that has substantially the same outer diameter as the outer diameter of a distal end portion of the tapered portion to the distal end portion of the tapered portion, and by applying heat to the dummy tube and stretching out the dummy tube, where the core rod is inserted inside the quartz tube.

Abstract: An electrode unit joining structure for a superconducting wire includes: a superconducting wire comprising a first base member, a first superconducting layer provided on the first base member, and a first electroconductive layer provided on the first superconducting layer; an electrode provided on the first electroconductive layer at an end portion of the superconducting wire; and a superconducting cover tape comprising a second base member, a second superconducting layer provided on the second base member, and a second electroconductive layer provided on the second superconducting layer, the superconducting cover tape being provided so as to cover at least part of the electrode, wherein the second electroconductive layer of the superconducting cover tape is disposed on the electrode side, and the electrode, the superconducting wire, and the superconducting cover tape are electrically connected to each other.

Abstract: A method for manufacturing an optical fiber grating that includes first and second gratings that configure an optical resonator, the method including: forming the first grating by radiating ultraviolet light to an optical fiber so that a irradiation intensity Z satisfies the following Equation 1: Z?(??S/x+0.04556 Y2+1.2225 Y)/(0.05625 Y2+1.6125 Y) . . . Equation 1, where, Z represents an irradiation intensity (mJ/mm2) of the ultraviolet light, ??S represents the maximum shift amount of a reflection center wavelength of the first grating that is allowed as long as reflection wavelengths of the first grating and second grating overlap each other, x represents a shift amount of the reflection center wavelength per temperature change of 1° C. (nm/° C.) in the first grating, and Y represents an intensity (W) of the wave-guided light.

Abstract: A method of forming a microstructure includes a Step (A) of forming a modified region in a substrate by irradiating a laser beam having a pulse duration on the order of picoseconds or shorter on a region where a pore-like microstructure is to be provided, and scanning a focal point at which the laser beam is converged; and a Step (B) of forming a microstructure by performing an etching process on the substrate in which the modified region has been formed, and removing the modified region, where a linear polarized laser beam is used as the laser beam in the Step (A), and the laser beam is irradiated so that an orientation of a linear polarization has a certain direction with respect to a direction of scanning the focal point.

Abstract: An optical fiber ribbon includes: a plurality of optical fibers arranged in parallel; and a tape material covering the plurality of optical fibers into a tape, in which the plurality of optical fibers are coated respectively with translucent color layers of different colors, and in at least two of the plurality of optical fibers, markings for identifying the optical fiber ribbon are provided at a same position in a longitudinal direction of the optical fiber ribbon.

Abstract: A microstructure forming method includes a step A of irradiating a region of a substrate, in which a hole-shaped or groove-shaped microstructure is to be formed, with a circularly or elliptically polarized laser beam having a pulse width of which the pulse duration is on the order of picoseconds or shorter, and scanning a focal point at which the laser beam converges to form a modified region, and a step B of performing an etching process on the substrate in which the modified region is formed and removing the modified region to form a microstructure.

Abstract: A waterproof connector (1) comprises: retainers (50) and (60) which include an inner receiving portion (91) formed on opposite surfaces (51) and (61) which face a wiring substrate (30); and a first seal member (70) which is filled in at least the inner receiving portion (91). An outer receiving portion (92) is formed on outer surfaces (55) and (65) and side surfaces (50d), (50e), (60d), and (60e) of the retainers (50) and (60). Defective portions (58) and (68), which pass from the outer surfaces (55) and (65) to the inner receiving portion (91), are formed in the retainers (50) and (60). The inner receiving portion (91) communicates with the outer receiving portion (92) at the side surfaces (50d), (50e), (60d), and (60e). The first seal member (70) includes: an inner seal portion (70a) which is received in the inner receiving portion (91); and; a defective seal portion (70d) and a side seal portion (70c) which are formed integrally with the inner seal portion (70a).

Abstract: A laser device includes: a semiconductor laser element having an output surface; an optical fiber having a leading end portion facing the output surface of the semiconductor laser element; and an optical fiber supporting member for supporting the optical fiber, the optical fiber supporting member being made from a non heat insulating material and having a bonding pad to which the optical fiber is fixed by use of solder. The optical fiber supporting member includes a contact portion thermally in contact with a base. The bonding pad is (i) spaced apart from the contact portion so as to be located on a side opposite from the contact portion so that a region to which laser light is applied from another laser element when the optical fiber is fixed to the bonding pad is sandwiched between the bonding pad and the base and (ii) separated spatially from the base.

Abstract: The invention aims to provide an optical fiber in which light that is input to the clad is easily released to the outside of the clad, and a laser device using the optical fiber. An optical fiber (50) includes a core (51), and a clad (52) coating the core (51). The clad (52) includes a refractive-index varying region (56) in which the refractive index increases in the direction from the inner circumferential side toward the outer circumferential side. In this structure, even when light is input to the clad (52), the light that has reached the refractive-index varying region (56) of the clad (52) is refracted and propagates from the inner circumferential side toward the outer circumferential side of the clad (52). Accordingly, light that is input to the clad (52) is easily released to the outside of the clad (52).

Abstract: A fiber laser system includes: a fiber laser device (10) including a fiber laser (11); a laser output end part (20); and a delivery fiber (30). The delivery fiber (30) is constituted by a double cladding fiber. On the output end side of the delivery fiber (30), there is provided an SFBG (31) which reflects part of laser light propagating in the core of the delivery fiber (30) to thereby couple the part of the laser light with a backward-propagating cladding mode propagating in a first cladding in a backward direction. On the input end side of the delivery fiber (30), there is provided a backward-propagating cladding mode detecting section (32) which detects the intensity of backward-propagating light in a cladding mode, which light is the part of the laser light coupled by the SFBG (31) with the backward-propagating cladding mode.

Abstract: The laser device includes a semiconductor laser element having an emission surface from which laser light is emitted, an optical fiber having an end part facing the emission surface, and an optical fiber supporting member which (i) supports the optical fiber and (ii) has a bonding pad to which the optical fiber is fixed by solder. The optical fiber supporting member includes a beam part having (i) a first main surface on which the bonding pad is provided and (ii) a second main surface opposite to the first main surface, and a pillar part which is fixed to a base and is joined to the beam part on an end portion of the beam part such that the second main surface and the base face each other while being spatially away from each other.

Abstract: A laser diode driving device (1) of the present invention includes: a variable DC power supply (3) for outputting a voltage for driving laser diodes (LD1 to LDn); a current driving element (4) for causing a current If to flow; a current control section (5) for controlling (i) turning on and off of the current driving element (4) and (ii) the amount of the current If; and a power supply control section (7) for controlling an output voltage of the variable DC power supply (3). The power supply control section (7) controls, on the basis of If-Vf characteristic data (D2), voltage drop characteristic data (D3), and Vds setting data (D4) all stored in a memory section (8), the output voltage of the variable DC power supply (3) so that the current driving element (4) has a constant inter-terminal voltage regardless of the amount of the current If.

Abstract: An optical fiber amplifier (2) includes: a first pumping source (10); a second pumping source (20); an amplification optical fiber (3) in which an active element is doped; a first optical filter (15) coupled to the first pumping source (10) and one end of the amplification optical fiber (30), the first optical filter (15) transmitting a light at a wavelength the same as the wavelength of a first pumping light and reflecting a light at a wavelength the same as the wavelength of a second pumping light; and a second optical filter (25) coupled to the second pumping source (20) and the other end of the amplification optical fiber (3), the second optical filter (25) transmitting a light at a wavelength the same as the wavelength of the second pumping light and reflecting a light at a wavelength the same as the wavelength of the first pumping light.

Abstract: The invention aims to provide a holey fiber that can release leak light propagating through the clad at a desired location, and a laser device using the holey fiber. A holey fiber includes: one end and the other end; a core; an inner clad coating the core; a hole layer having a large number of holes formed therein and coating the inner clad; and an outer clad coating the hole layer. In this holey fiber, a collapse region is formed, and the holes in the collapse region are squashed by a predetermined length in the length direction of the fiber.