Abstract: A ScAlMgO4 monocrystalline substrate that is highly cleavable and that does not easily cause cracking in the GaN film id grown on the substrate and a method for manufacturing such a ScAlMgO4 monocrystalline substrate are provided. The ScAlMgO4 monocrystalline substrate has a crystal oxygen concentration of 57 atom % or less as measured by inductively coupled plasma atomic emission spectroscopy analysis.

Abstract: A light source apparatus includes: a base part; an anisotropic heat conductive sheet whose thermal conductivity in a surface direction is higher than a thermal conductivity in a thickness direction, the anisotropic heat conductive sheet including a first surface that makes contact with a surface of the base part; a laser diode module disposed at a second surface on a side opposite to the first surface in the anisotropic heat conductive sheet, and configured to emit laser light; and a cooling member disposed at the second surface and separated from the laser diode module, wherein a refrigerant flows inside the cooling member.

Abstract: A RAMO4 substrate that does not easily crack during or after the formation of group III nitride crystal includes a single crystal represented by general formula RAMO4 (wherein R represents one or more trivalent elements selected from the group consisting of Sc, In, Y, and lanthanoid elements, A represents one or more trivalent elements selected from the group consisting of Fe(III), Ga, and Al, and M represents one or more divalent elements selected from the group consisting of Mg, Mn, Fe(II), Co, Cu, Zn, and Cd). The RAMO4 substrate has a crystal plane with a curvature radius r of 52 m or more, and a square value of correlation coefficient ? of 0.81 or more. The curvature radius r is calculated as an absolute value from X-ray peak position ?i and measurement position Xi after the measurements of X-ray peak positions ?i at a plurality of positions Xi lying on a straight line passing through the center of the RAMO4 substrate.

Abstract: A wavelength conversion device including a cavity that includes an RAMO4 crystal having a single crystal represented by a first general formula of RAMO4, a laser crystal, and a mirror, in which in the first general formula, R represents one or a plurality of trivalent elements selected from the group consisting of Sc, In, Y, and lanthanoid elements, A represents one or a plurality of trivalent elements selected from the group consisting of Fe (III), Ga, and Al, and M represents one or a plurality of divalent elements selected from the group consisting of Mg, Mn, Fe (II), Co, Cu, Zn, and Cd.

Abstract: A RAMO4 substrate includes a single crystal represented by a formula of RAMO4 (in the formula, R indicates one or a plurality of trivalent elements selected from a group consisting of Sc, In, Y, and a lanthanoid element, A indicates one or a plurality of trivalent elements selected from a group consisting of Fe(III), Ga, and Al, and M indicates one or a plurality of bivalent elements selected from a group consisting of Mg, Mn, Fe(II), Co, Cu, Zn, and Cd). An epitaxially-grown surface is provided on one surface of the RAMO4 substrate, a satin-finish surface is provided on another surface. The satin-finish surface has surface roughness which is larger than that of the epitaxially-grown surface.

Abstract: The object of the present invention is to provide a Group III nitride semiconductor light emitting diode having improved light extraction efficiency. A Group III nitride semiconductor light emitting diode according to the present disclosure includes an RAMO4 layer including a single crystal represented by the general formula RAMO4 (wherein R represents one or more trivalent elements selected from the group consisting of Sc, In, Y and lanthanoid elements, A represents one or more trivalent elements selected from the group consisting of Fe (III), Ga and Al, and M represents one or more divalent elements selected from the group consisting of Mg, Mn, Fe (II), Co, Cu, Zn and Cd); and a layered product stacked on the RAMO4 layer. The layered product includes at least a light emitting layer including a Group III nitride semiconductor.

Abstract: A laser oscillator includes a first laser diode that emits first laser light, a second laser diode that emits second laser light having a wavelength different from a wavelength of the first laser light, a first current source that drives the first laser diode, a second current source that drives the second laser diode, a combiner that superimposes the first laser light with the second laser light, and an output mirror that emits laser light combined by the combiner to the outside.

Abstract: Provided herein is a wavelength converter capable of producing shorter wavelengths by wavelength conversion than in related art. A wavelength converter of the present disclosure includes: a first layer formed of a single crystal represented by general formula RAMO4; and a second layer formed of a single crystal represented by the general formula RAMO4 and having a direction of polarization reversed 180° from a direction of polarization of the first layer, wherein, in the general formula, R represents one or more trivalent elements selected from the group consisting of Sc, In, Y, and a lanthanoid element, A represents one or more trivalent elements selected from the group consisting of Fe(III), Ga, and Al, and M represents one or more divalent elements selected from the group consisting of Mg, Mn, Fe(II), Co, Cu, Zn, and Cd.

Abstract: A Group III nitride semiconductor for growing a high-quality crystal having a low defect density and a method for producing the Group III nitride semiconductor. The Group III nitride semiconductor includes an RAMO4 substrate including a single crystal represented by the general formula RAMO4 (where R represents one or more trivalent elements selected from the group consisting of Sc, In, Y and lanthanoid elements, A represents one or more trivalent elements selected from the group consisting of Fe(III), Ga and Al, and M represents one or more divalent elements selected from the group consisting of Mg, Mn, Fe(II), Co, Cu, Zn and Cd); a p-type Group III nitride crystal layer disposed on the RAMO4 substrate; a plurality of n-type Group III nitride crystal layers disposed on the p-type Group III nitride crystal layer; and a Group III nitride crystal layer disposed on the n-type Group III nitride crystal layers.

Abstract: A group-III nitride semiconductor laser device includes a GaN substrate, and an active layer provided on the GaN substrate, in which the GaN substrate has an oxygen concentration of 5×1019 cm?3 or more, and an absorption coefficient of the GaN substrate with respect to an oscillation wavelength of the active layer is greater than an absorption coefficient of the active layer with respect to the oscillation wavelength.

Abstract: To provide a high-quality group III nitride semiconductor. A group III nitride semiconductor including an n-GaN layer composed of AlxGa1-xN (0?x<1), an InGaN layer disposed on the n-GaN layer and composed of InGaN, an n-AlGaN layer disposed on the InGaN layer and composed of n-type AlyGa1-yN (0?y<1), and a functional layer disposed on the n-AlGaN layer, wherein the concentration of Mg in the n-GaN layer is higher than the concentration of Mg in the n-AlGaN layer.

Abstract: A wavelength conversion device including a cavity that includes an RAMO4 crystal having a single crystal represented by a first general formula of RAMO4, a laser crystal, and a mirror, in which in the first general formula, R represents one or a plurality of trivalent elements selected from the group consisting of Sc, In, Y, and lanthanoid elements, A represents one or a plurality of trivalent elements selected from the group consisting of Fe (III), Ga, and Al, and M represents one or a plurality of divalent elements selected from the group consisting of Mg, Mn, Fe (II), Co, Cu, Zn, and Cd.

Abstract: Provided herein is a wavelength converter capable of producing shorter wavelengths by wavelength conversion than in related art. A wavelength converter of the present disclosure includes: a first layer formed of a single crystal represented by general formula RAMO4; and a second layer formed of a single crystal represented by the general formula RAMO4 and having a direction of polarization reversed 180° from a direction of polarization of the first layer, wherein, in the general formula, R represents one or more trivalent elements selected from the group consisting of Sc, In, Y, and a lanthanoid element, A represents one or more trivalent elements selected from the group consisting of Fe(III), Ga, and Al, and M represents one or more divalent elements selected from the group consisting of Mg, Mn, Fe(II), Co, Cu, Zn, and Cd.

Abstract: A ScAlMgO4 monocrystalline substrate that is highly cleavable and that does not easily cause cracking in the GaN film id grown on the substrate and a method for manufacturing such a ScAlMgO4 monocrystalline substrate are provided. The ScAlMgO4 monocrystalline substrate has a crystal oxygen concentration of 57 atom % or less as measured by inductively coupled plasma atomic emission spectroscopy analysis.

Abstract: A RAMO4 substrate that does not easily crack during or after the formation of group III nitride crystal includes a single crystal represented by general formula RAMO4 (wherein R represents one or more trivalent elements selected from the group consisting of Sc, In, Y, and lanthanoid elements, A represents one or more trivalent elements selected from the group consisting of Fe(III), Ga, and Al, and M represents one or more divalent elements selected from the group consisting of Mg, Mn, Fe(II), Co, Cu, Zn, and Cd). The RAMO4 substrate has a crystal plane with a curvature radius r of 52 m or more, and a square value of correlation coefficient ? of 0.81 or more. The curvature radius r is calculated as an absolute value from X-ray peak position ?i and measurement position Xi after the measurements of X-ray peak positions ?i at a plurality of positions Xi lying on a straight line passing through the center of the RAMO4 substrate.

Abstract: A Group III nitride semiconductor for growing a high-quality crystal having a low defect density and a method for producing the Group III nitride semiconductor. The Group III nitride semiconductor includes an RAMO4 substrate including a single crystal represented by the general formula RAMO4 (where R represents one or more trivalent elements selected from the group consisting of Sc, In, Y and lanthanoid elements, A represents one or more trivalent elements selected from the group consisting of Fe(III), Ga and Al, and M represents one or more divalent elements selected from the group consisting of Mg, Mn, Fe(II), Co, Cu, Zn and Cd); a p-type Group III nitride crystal layer disposed on the RAMO4 substrate; a plurality of n-type Group III nitride crystal layers disposed on the p-type Group III nitride crystal layer; and a Group III nitride crystal layer disposed on the n-type Group III nitride crystal layers.

Abstract: To provide a high-quality group III nitride semiconductor. A group III nitride semiconductor including an n-GaN layer composed of AlxGa1?xN(0?x<1), an InGaN layer disposed on the n-GaN layer and composed of InGaN, an n-AlGaN layer disposed on the InGaN layer and composed of n-type AlyGa1?yN (0?y<1), and a functional layer disposed on the n-AlGaN layer, wherein the concentration of Mg in the n-GaN layer is higher than the concentration of Mg in the n-AlGaN layer.

Abstract: The object of the present invention is to provide a Group III nitride semiconductor light emitting diode having improved light extraction efficiency. A Group III nitride semiconductor light emitting diode according to the present disclosure includes an RAMO4 layer including a single crystal represented by the general formula RAMO4 (wherein R represents one or more trivalent elements selected from the group consisting of Sc, In, Y and lanthanoid elements, A represents one or more trivalent elements selected from the group consisting of Fe (III), Ga and Al, and M represents one or more divalent elements selected from the group consisting of Mg, Mn, Fe (II), Co, Cu, Zn and Cd); and a layered product stacked on the RAMO4 layer. The layered product includes at least a light emitting layer including a Group III nitride semiconductor.

Abstract: A RAMO4 substrate is formed from single crystal represented by a formula of RAMO4 (in the formula, R indicates one or a plurality of trivalent elements selected from a group consisting of Sc, In, Y, and a lanthanoid element, A indicates one or a plurality of trivalent elements selected from a group consisting of Fe(III), Ga, and Al, and M indicates one or a plurality of bivalent elements selected form a group consisting of Hg, Mn, Fe(II), Co, Cu, Zn, and Cd). An epitaxially-grown surface is provided on at least one surface of the RAMO4 substrate. The epitaxially-grown surface includes a plurality of cleavage surfaces which are regularly distributed, and are separated from each other.

Abstract: On an RAMO4 substrate containing a single crystal represented by the general formula RAMO4 (wherein R represents one or a plurality of trivalent elements selected from a group of elements including: Sc, In, Y, and a lanthanoid element, A represents one or a plurality of trivalent elements selected from a group of elements including: Fe(III), Ga, and Al, and M represents one or a plurality of divalent elements selected from a group of elements including: Mg, Mn, Fe(II), Co, Cu, Zn, and Cd), a buffer layer containing a nitride of In and a Group III element except for In is formed, and a Group III nitride crystal is formed on the buffer layer.