Abstract: An optical device includes: a thermal conductor; a support that is separated from the thermal conductor and that has a coefficient of thermal expansion lower than a coefficient of thermal expansion of the thermal conductor; and an optical fiber that thermally contacts with the thermal conductor via a resin covering a jacket-removed section of the optical fiber and that is fixed to the support in each of two jacketed sections of the optical fiber, wherein the two jacketed sections are adjacent to the jacket-removed section.

Abstract: A laser apparatus includes: a monitoring device that includes a detector that detects light belonging to a first wavelength range including a peak wavelength of at least one of Stokes light and anti-Stokes light, in preference to light belonging to a second wavelength range; and a multi-mode fiber. The Stokes light and the anti-Stokes light result from, in the multi-mode fiber that guides laser light, four-wave mixing in which a plurality of guide modes are involved.

Abstract: An aspect of the present invention makes it easier to increase a temperature of metal powder to a temperature at which a powder bed (PB) is sintered or melted. An irradiation device (13) includes: a galvano scanner (13a) which irradiates at least part of a powder bed (PB) with laser light; and a wavelength converting element (WCE) provided in an optical path of the laser light. The wavelength converting element (WCE) converts laser light inputted into the wavelength converting element to laser light containing harmonic wave light (HL) which has a shorter wavelength than the laser light inputted into the wavelength converting element.

Abstract: The present invention causes residual stress, which may be generated in a metal shaped object (MO), to be small. A metal shaping device includes an irradiation device (13, 13A). The irradiation device (13, 13A), which is configured to irradiate a powder bed (PB) containing a metal powder with laser light (L), is able to be switched between (i) a focused state in which a beam spot diameter (D1) of laser light (L) on a surface of the powder bed (PB) has a first value and (ii) a defocused state in which the beam spot diameter (D2) of the laser light (L) on the surface of the powder bed (PB) has a second value which is larger than the first value.

Abstract: The present invention causes residual stress, which may be generated in a metal shaped object (MO), to be small. An irradiation device (13) includes: a first irradiating section (13A) configured to irradiate, with first laser light (LA), a first region (DA) of a powder bed (PB); and second irradiating section (13B) configured to irradiate, with second laser light (LB), a second region (DB) of the powder bed (PB). The second irradiating section (13B) irradiates the second region (DB) with the second laser light (LB) so that an energy density of the second laser light (LB), with which the second region (DB) is irradiated, is lower than an energy density of the first laser light (LA), with which the first region (DA) is irradiated.

Abstract: The present invention keeps a residual stress small which may occur in a metal shaped object (MO) while keeping a time short which is to be taken for carrying out main heating and preheating. An irradiation device (13) carries out a first heating step of heating a powder bed (PB) with laser light (LL) so that a temperature (T) of the powder bed (PB) is higher than 0.8 times as high as a melting point (Tm) of the metal powder and a second heating step of heating the powder bed (PB) with cladding light (CL) before or after the first heating step so that a temperature (T) of the powder bed (PB) is 0.5 times to 0.8 times as high as the melting point (Tm) of the metal powder.

Abstract: A fiber laser apparatus includes a pump light source that emits pump light; a pump delivery fiber that guides the pump light; an amplifying optical fiber that is optically coupled to the pump delivery fiber and guides laser light; and a filter element that causes more loss of light of a wavelength range that includes a peak wavelength of at least one of Stokes light and anti-Stokes light than the laser light. The Stokes light and anti-Stokes light result from four-wave mixing involving a plurality of guide modes in a multi-mode fiber that guides the laser light. The filter element is disposed between: the pump delivery fiber and the amplifying optical fiber, the amplifying optical fiber and the multi-mode fiber, or at the multi-mode fiber.

Abstract: In a case where a variation in reflection resistance among fiber lasers occurs, a reflection resistance of a fiber laser system as a whole is restored by reducing the variation while maintaining an output power of the fiber laser system as a whole. The fiber laser system includes a control section (C) configured to increase a proportion of a backward excitation power (PBi) in a fiber laser (FLi) so that fiber lasers (FL1 through FLn) less vary in reflection resistance.

Abstract: An optical power monitor device includes a first optical fiber, including a core and a cladding surrounding the core and being at least one of an incidence-side optical fiber and a launch-side optical fiber connected to each other at a connection point, which is constituted by a curve portion and a linear portion between the curve portion and the connection point, a low refractive index layer that is provided in at least a portion of the linear portion on an outer side of the cladding and has a refractive index lower than a refractive index of the cladding, and a first optical detector that is provided at a position close to at least the curve portion.

Abstract: A composite structure includes a stepped portion formed by laminating a plurality of plies with end surfaces thereof being shifted from each other. The composite structure includes a body portion which includes a first structure portion where a first ply is laminated on a top layer of the first structure portion, a second structure portion where a second ply is laminated on a top layer of the second structure portion, and the stepped portion disposed between the first structure portion and the second structure portion, the second ply being positioned at a distance from the first ply in a lamination direction, and a first cover ply which includes a covering portion covering the stepped portion, one end portion, and the other end portion and is formed so as to cover only a part of a surface of the first ply or a part of a surface of the second ply.

Abstract: A fiber laser apparatus includes a pumping light source which launches pumping light, an amplifying optical fiber which includes a core and a noncircular cladding, and absorbs the pumping light to launch laser light, an amplifying coil which has a configuration around which the amplifying optical fiber is wound, a first reflector which is provided on an input side of the amplifying coil and is configured to reflect the laser light toward the amplifying coil, and a second reflector which is provided on a launching side of the amplifying coil, has a lower reflectance than a reflectance of the first reflector, and is configured to reflect the laser light toward the amplifying coil.

Abstract: Reflection resistances of respective fiber lasers in a state where an entire fiber laser system is in operation are evaluated. Each of fiber lasers (2 through 4) includes (i) a laser beam measuring section (28) configured to measure a power of a laser beam which a low reflection FBG (26) has transmitted therethrough and (ii) a Stokes beam measuring section (29) configured to measure a power of a Stokes beam which a high reflection FBG (24) has transmitted therethrough.

Abstract: In a case where a variation in reflection resistance among fiber lasers occurs, a reflection resistance of a fiber laser system as a whole is restored by reducing the variation while maintaining an output power of the fiber laser system as a whole. The fiber laser system includes a control section (C) configured to increase a proportion of a backward excitation power (PBi) in a fiber laser (FLi) so that fiber lasers (FL1 through FLn) less vary in reflection resistance.

Abstract: The present invention achieves a fiber laser having a high reflection resistance. A length of an optical fiber MMF is set so that a condition is satisfied at each point on an individual optical path of a fiber laser (FL2), the condition being that a difference between time at which a power of a forward Stokes beam (SF) is at a maximum value and time at which a power of a backward Stokes beam (SB) is at a maximum value is greater than a sum of a half width at half maximum of the power of the forward Stokes beam (SF) and a half width at half maximum of the power of the backward Stokes beam (SB).

Abstract: In a fiber laser system (1) for outputting a laser beam obtained by combining a plurality of laser beams outputted by driving the respective fiber laser unit (2a, 2b, 2c), a control section (7) controls a plurality of current sources (6a, 6b, 6c) so that there are time intervals of a certain time between peaks which appear in a case where respective powers of the laser beams rise.

Abstract: An optical device 30 has a GRIN lens 35, a preceding-stage optical fiber 31 from which a light beam is entered to the GRIN lens 35, and a subsequent-stage optical fiber 32 to which a light beam emitted from the GRIN lens 35 is entered. A method for adjusting beam quality includes a measurement process P2 in which a light beam is entered to the preceding-stage optical fiber 31 and the beam quality of a light beam to be emitted from the subsequent-stage optical fiber 32 through the GRIN lens 35 is measured, and an adjustment process P3 in which the length of the GRIN lens 35 is adjusted on the basis of a result in the measurement process P2.

Abstract: In a composite material structure, which is configured as a fiber-reinforced plastic composite material extending in one direction and having a plurality of holes defined at intervals in a row in the one direction and which is subjected to a tensile load and/or a compressive load in the one direction, a peripheral region around the holes comprises a first area obtained by bending composite material, which is reinforced using continuous fibers that have been made even in a longitudinal direction, so that a center line of a width of the composite material weaves between adjacent holes and zigzags in the one direction. A tensile rigidity and/or a compressive rigidity in the one direction of the peripheral region around the holes is lower than a tensile rigidity and/or a compressive rigidity in the one direction of other regions that surround the peripheral region.

Abstract: A joint structure (1) for a composite member made from a composite material. The joint structure includes a plate for increasing thickness (40a, 40b) adhered to at least one side of the composite member (10). The composite member (10) and a counterpart member (20) are fastened together by inserting and fixing a fastener member (30) into a through-hole (24, 26) formed through the composite member (10), the plate for increasing thickness (40a, 40b), and the counterpart member (20) to be joined to the composite member.

Abstract: Reflection resistances of respective fiber lasers in a state where an entire fiber laser system is in operation are evaluated. Each of fiber lasers (2 through 4) includes (i) a laser beam measuring section (28) configured to measure a power of a laser beam which a low reflection FBG (26) has transmitted therethrough and (ii) a Stokes beam measuring section (29) configured to measure a power of a Stokes beam which a high reflection FBG (24) has transmitted therethrough.

Abstract: A bridge fiber includes a core layer and an outer layer which has an index of refraction higher than that of the core layer and covers the outer peripheral surface of the core layer. The outer layer is surrounded by a substance such as the atmosphere having an index of refraction lower than an index of refraction n2 of the outer layer. An area AR1 of the outer layer at one end face of the bridge fiber is an area that is to be optically coupled to an end face of a core of each of a plurality of pumping light inputting optical fibers, while an area AR2 of the core layer at another end face of the bridge fiber is an area that is to be optically coupled to an end face of a core of an amplification optical fiber.