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: An optical waveguide element includes a core and a cladding that is made of SiO2. When ng_i_TE is a group refractive index of a TE0 polarized wave in the i-th waveguide counted from a light incidence plane of the core and ng_i_TM is a group refractive index of a TM0 polarized wave in the i-th waveguide, the length L—i[m] of the i-th waveguide satisfies a predetermined relation.

Abstract: An optical waveguide device includes: a mode splitter including a main waveguide in which lights can be propagated in at least two propagation modes with different propagation orders and a subsidiary waveguide which includes a coupling section disposed in parallel with the main waveguide at a certain distance away from the main waveguide so as to constitute a directional coupler and is capable of splitting at least one propagation mode out of the two or more propagation modes from the main waveguide. Also, ncore/ncladding which is a refractive index ratio between a core and a cladding which constitute the main waveguide and the subsidiary waveguide is in a range of 101% to 250%.

Abstract: An optical modulation device configured of a planar optical waveguide, includes: a light incidence unit which allows light to be incident on the planar optical waveguide; a Mach-Zehnder interferometer which includes a first optical splitter section branching the light incident on the light incidence unit, two arm portions guiding the light branched by the first optical splitter section, a phase modulation unit linearly disposed on each of the two arm portions, and a first optical coupler section combining the light guided from the two arm portions; a light launching unit which launches the light combined by the first optical coupler section from the planar optical waveguide; and a traveling-wave electrode which includes an input unit and an output unit, and applies a voltage to the phase modulation unit.

Abstract: An optical waveguide element includes a core and a cladding that is made of SiO2. When ng_i_TE is a group refractive index of a TE0 polarized wave in the i-th waveguide counted from a light incidence plane of the core and ng_i_TM is a group refractive index of a TM0 polarized wave in the i-th waveguide, the length L_i[m] of the i-th waveguide satisfies a predetermined relation.

Abstract: A high-order polarization conversion device configured of a planar optical waveguide, includes: a substrate; a lower clad disposed on the substrate; a core including a lower core and an upper core, the lower core being disposed on the lower clad and having a fixed height in a rectangular sectional shape, the upper core being formed of the same material as the lower core and having a fixed height in a rectangular sectional shape that is disposed continuously on the lower core; and an upper clad that is disposed on the core and the lower clad and is formed of the same material as the lower clad. The high-order polarization conversion device performs high-order polarization conversion between TE1 of the start portion and TM0 of the end portion.

Abstract: A polarization conversion element is disclosed in which an optical waveguide formed on a substrate sequentially includes a first waveguide portion, a polarization rotation portion, and a second waveguide portion, an effective refractive index of a TE mode having the highest effective refractive index in an eigen mode of waveguide light on a sectional surface of the first waveguide portion is higher than an effective refractive index of a TM mode having the highest effective refractive index, an effective refractive index of the TM mode having the highest effective refractive index on a sectional surface of the second waveguide portion is higher than an effective refractive index of the TE mode having the highest effective refractive index, and heights of waveguide structures (for example, cores) of the first waveguide portion and the second waveguide portion are equal to each other.

Abstract: An optical waveguide element includes: a rib waveguide and a pair of slab portions including a first slab portion and a second slab portion connected to both sides of the rib portion so as to sandwich the rib portion. The rib portion has a cross-sectional dimension which allows the propagation of a fundamental mode and a higher order mode in a predetermined single polarization state, and has a first P-type semiconductor and a first N-type semiconductor forming a PN junction, the first slab portion has a second P-type semiconductor and a P-type conductor connected to each other, the second P-type semiconductor is connected to the first P-type semiconductor of the rib portion, the second slab portion has a second N-type semiconductor and an N-type conductor connected to each other, and the second N-type semiconductor is connected to the first N-type semiconductor of the rib portion.

Abstract: A high-order polarization conversion device configured of a planar optical waveguide, includes: a substrate; a lower clad disposed on the substrate; a core including a lower core and an upper core, the lower core being disposed on the lower clad and having a fixed height in a rectangular sectional shape, the upper core being formed of the same material as the lower core and having a fixed height in a rectangular sectional shape that is disposed continuously on the lower core; and an upper clad that is disposed on the core and the lower clad and is formed of the same material as the lower clad. The high-order polarization conversion device performs high-order polarization conversion between TE1 of the start portion and TM0 of the end portion.

Abstract: A polarization conversion element is disclosed in which an optical waveguide formed on a substrate sequentially includes a first waveguide portion, a polarization rotation portion, and a second waveguide portion, an effective refractive index of a TE mode having the highest effective refractive index in an eigen mode of waveguide light on a sectional surface of the first waveguide portion is higher than an effective refractive index of a TM mode having the highest effective refractive index, an effective refractive index of the TM mode having the highest effective refractive index on a sectional surface of the second waveguide portion is higher than an effective refractive index of the TE mode having the highest effective refractive index, and heights of waveguide structures (for example, cores) of the first waveguide portion and the second waveguide portion are equal to each other.

Abstract: A planar optical waveguide device, includes: two input portions that are waveguides that have the same width, are parallel to each other, and have rectangular cross-sections; a wide portion that is a linear waveguide and is connected after the two input portions; a tapered portion that is connected after the wide portion and that is a multi-mode waveguide which has a tapered shape having a width decreasing gradually and through which at least TE1 propagates; and an output portion that is connected after the tapered portion and that is a multi-mode waveguide which has a rectangular cross-section and through which at least TE1 propagates. The planar optical waveguide device forms a high-order mode conversion combining element that outputs the TE0, which is input to the two input portions, as the TE1 from the output portion.

Abstract: An optical modulation device configured of a planar optical waveguide, includes: a light incidence unit which allows light to be incident on the planar optical waveguide; a Mach-Zehnder interferometer which includes a first optical splitter section branching the light incident on the light incidence unit, two arm portions guiding the light branched by the first optical splitter section, a phase modulation unit linearly disposed on each of the two arm portions, and a first optical coupler section combining the light guided from the two arm portions; a light launching unit which launches the light combined by the first optical coupler section from the planar optical waveguide; and a traveling-wave electrode which includes an input unit and an output unit, and applies a voltage to the phase modulation unit.

Abstract: An optical waveguide element includes: a rib waveguide and a pair of slab portions including a first slab portion and a second slab portion connected to both sides of the rib portion so as to sandwich the rib portion. The rib portion has a cross-sectional dimension which allows the propagation of a fundamental mode and a higher order mode in a predetermined single polarization state, and has a first P-type semiconductor and a first N-type semiconductor forming a PN junction, the first slab portion has a second P-type semiconductor and a P-type conductor connected to each other, the second P-type semiconductor is connected to the first P-type semiconductor of the rib portion, the second slab portion has a second N-type semiconductor and an N-type conductor connected to each other, and the second N-type semiconductor is connected to the first N-type semiconductor of the rib portion.

Abstract: An optical waveguide device includes: a mode splitter including a main waveguide in which lights can be propagated in at least two propagation modes with different propagation orders and a subsidiary waveguide which includes a coupling section disposed in parallel with the main waveguide at a certain distance away from the main waveguide so as to constitute a directional coupler and is capable of splitting at least one propagation mode out of the two or more propagation modes from the main waveguide. Also, ncore/ncladding which is a refractive index ratio between a core and a cladding which constitute the main waveguide and the subsidiary waveguide is in a range of 101% to 250%.

Abstract: A planar optical waveguide device, includes: two input portions that are waveguides that have the same width, are parallel to each other, and have rectangular cross-sections; a wide portion that is a linear waveguide and is connected after the two input portions; a tapered portion that is connected after the wide portion and that is a multi-mode waveguide which has a tapered shape having a width decreasing gradually and through which at least TE1 propagates; and an output portion that is connected after the tapered portion and that is a multi-mode waveguide which has a rectangular cross-section and through which at least TE1 propagates. The planar optical waveguide device forms a high-order mode conversion combining element that outputs the TE0, which is input to the two input portions, as the TE1 from the output portion.

Abstract: A polarization conversion device includes: a directional coupler that includes an input side optical waveguide and an output side optical waveguide which are disposed in parallel to each other and each of which has a core. Assuming that a direction in which the input side optical waveguide and the output side optical waveguide face each other is a width direction and a direction perpendicular to the width direction is a height direction in a cross section perpendicular to a longitudinal direction of each of the input side optical waveguide and the output side optical waveguide, and the directional coupler is configured to couple first light guided through the input side optical waveguide to second light guided through the output side optical waveguide, the polarization direction of the second light is perpendicular to that of the first light.

Abstract: A polarization conversion device includes: a directional coupler that includes an input side optical waveguide and an output side optical waveguide which are disposed in parallel to each other and each of which has a core Assuming that a direction in which the input side optical waveguide and the output side optical waveguide face each other is a width direction and a direction perpendicular to the width direction is a height direction in a cross section perpendicular to a longitudinal direction of each of the input side optical waveguide and the output side optical waveguide, and the directional coupler is configured to couple first light guided through the input side optical waveguide to second light guided through the output side optical waveguide, the polarization direction of the second light is perpendicular to that of the first light.

Abstract: Disclosed is a method of producing an insulated electric wire, in which a primary coating layer including at least an enamel-baking layer is formed on a metallic conductor to form a primary coated electric wire, and a secondary coating layer is extrusion-formed on the primary coating layer of the primary coated electric wire. The method includes an electric wire pre-heating process where a surface of the primary coating layer is pre-heated using an electric wire pre-heating unit, and a resin extrusion process where a secondary coating layer is extrusion-formed on the pre-heated primary coating layer using a resin extrusion unit. Further disclosed is an apparatus for producing an insulated electric wire.