Abstract: A wavelength conversion element 20 has a periodic polarization reversal structure formed in a non-linear optical crystal, wherein positive/negative polarity is periodically alternated in period d expressed by the following formula (1), outputs light having frequency of 2? from the incident light having frequency of ?, and is characterized in that the non-linear optical crystal is a nitride single crystal: d=m?/[2(n2??n?)]??(1) where, m represents the order of phase matching, ? represents the wavelength of the incident light, n? represents the refractive index of the nitride single crystal such as AlN for the light having frequency of ?, and n2? represents the refractive index of the nitride single crystal such as AlN for the light having frequency of 2?.

Abstract: A light emitting element has a substrate of gallium oxides and a pn-junction formed on the substrate. The substrate is of gallium oxides represented by: (AlXInYGa(1-X-Y))2O3 where 0?x?1, 0?y?1 and 0?x+y?1. The pn-junction has first conductivity type substrate, and GaN system compound semiconductor thin film of second conductivity type opposite to the first conductivity type.

Abstract: The present invention provides a garnet single crystal comprising a terbium aluminum garnet single crystal, wherein a portion of the aluminum is substituted with scandium, and a portion of at least one of the aluminum and terbium is substituted with at least one type selected from the group consisting of thulium, ytterbium and yttrium.

Abstract: A method of growing a p-type thin film of ?-Ga2O3 includes preparing a substrate including a ?-Ga2O3 single crystal, and growing a p-type thin film of ?-Ga2O3 on the substrate. The p-type thin film is grown in a manner that Ga in the thin film is replaced by a p-type dopant selected from H, Li, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, Mn, Fe, Co, Ni, Pd, Cu, Ag, Au, Zn, Cd, Hg, Tl, and Pb.

Abstract: The inorganic optical filter of the invention consists of a NdF3 single crystal. The optical element of the invention comprises a wavelength conversion element wherein incident light is subjected to wavelength conversion to twice the frequency by quasi-phase-matching using primary matching or tertiary matching, and emitted, and an inorganic optical filter situated in the optical path of light emitted from the wavelength conversion element, wherein the wavelength conversion element consists of a ferroelectric fluoride single crystal represented by Ba1?y(Mg1?xZnx)1+yF4 (where 0?x?1, and ?0.2?y?0.2), and the inorganic optical filter consists of a NdF3 single crystal.

Abstract: A thin-film single crystal growing method includes preparing a substrate, irradiating an excitation beam on a metallic target made of a pure metal or an alloy in a predetermined atmosphere, and combining chemical species including any of atoms, molecules, and ions released from the metallic target by irradiation of the excitation beam with atoms contained in the predetermined atmosphere to form a thin film on the substrate.

Abstract: The present invention provides a single crystal for an optical isolator having a Faraday rotation angle exceeding that of TGG single crystal in a wavelength region of 1064 nm or longer or in a wavelength region of shorter than 1064 nm, and is capable of realizing enlargement of crystal size, a production process thereof, an optical isolator, and an optical processor that uses the optical isolator. The single crystal according to the present invention is composed of a terbium aluminum garnet single crystal, and mainly a portion of the aluminum is replaced with lutetium.

Abstract: A light-emitting element includes a ?-Ga2O3 substrate, a GaN-based semiconductor layer formed on the ?-Ga2O3 substrate, and a double-hetero light-emitting layer formed on the GaN-based semiconductor layer.

Abstract: A garnet-type single crystal is represented by a general formula, A3B2C3O12 (having a crystal structure with three sites A, B and C occupied by cations, wherein A represents an element occupying the site A, B represents an element occupying the site B, C represents an element occupying the site C, O represents an oxygen atom), and contains fluorine, in which the fluorine attains any one or both of substituting for the oxygen atom or compensating for oxygen defect.

Abstract: To provide a semiconductor layer in which a GaN system epitaxial layer having high crystal quality can be obtained. The semiconductor layer includes a ?-Ga2O3 substrate 1 made of a ?-Ga2O3 single crystal, a GaN layer 2 formed by subjecting a surface of the ?-Ga2O3 substrate 1 to nitriding processing, and a GaN growth layer 3 formed on the GaN layer 2 through epitaxial growth by utilizing an MOCVD method. Since lattice constants of the GaN layer 2 and the GaN growth layer 3 match each other, and the GaN growth layer 3 grows so as to succeed to high crystalline of the GaN layer 2, the GaN growth layer 3 having high crystalline is obtained.

Abstract: A wavelength conversion element 20 has a periodic polarization reversal structure formed in a non-linear optical crystal, wherein positive/negative polarity is periodically alternated in period d expressed by the following formula (1), outputs light having frequency of 2? from the incident light having frequency of ?, and is characterized in that the non-linear optical crystal is a nitride single crystal: d=m?/[2(n2??n?)]??(1) where, m represents the order of phase matching, ? represents the wavelength of the incident light, n? represents the refractive index of the nitride single crystal such as AlN for the light having frequency of ?, and n2? represents the refractive index of the nitride single crystal such as AlN for the light having frequency of 2?.

Abstract: To provide a Ga2O3 compound semiconductor device in which a Ga2O3 system compound is used as a semiconductor, which has an electrode having ohmic characteristics adapted to the Ga2O3 system compound, and which can make a heat treatment for obtaining the ohmic characteristics unnecessary. An n-side electrode 20 including at least a Ti layer is formed on a lower surface of an n-type ?-Ga2O3 substrate 2 by utilizing a PLD method. This n-side electrode 20 has ohmic characteristics at 25° C. The n-side electrode 20 may have two layer including a Ti layer and an Au layer, three layers including a Ti layer, an Al layer and an Au layer, or four layers including a Ti layer, an Al layer, a Ni layer and an Au layer.

Abstract: A thin-film single crystal growing method includes preparing a substrate, irradiating an excitation beam on a metallic target made of a pure metal or an alloy in a predetermined atmosphere, and combining chemical species including any of atoms, molecules, and ions released from the metallic target by irradiation of the excitation beam with atoms contained in the predetermined atmosphere to form a thin film on the substrate.

Abstract: To provide a method of controlling a conductivity of a Ga2O3 system single crystal with which a conductive property of a ?-Ga2O3 system single crystal can be efficiently controlled. The light emitting element includes an n-type ?-Ga2O3 substrate, and an n-type ?-AlGaO3 cladding layer, an active layer, a p-type ?-AlGaO3 cladding layer and a p-type ?-Ga2O3 contact layer which are formed in order on the n-type ?-Ga2O3 substrate. A resistivity is controlled to fall within the range of 2.0×10?3 to 8×102 ?cm and a carrier concentration is controlled to fall within the range of 5.5×1015 to 2.0×1019/cm3 by changing a Si concentration within the range of 1×10?5 to 1 mol %.

Abstract: A method for growing a ?-Ga2O3 single includes preparing a ?-Ga2O3 seed crystal and growing the ?-Ga2O3 single crystal from the ?-Ga2O3 seed crystal in a predetermined direction.

Abstract: An object of the invention is to provide an iodide single crystal material that provides a scintillator material for the next-generation TOF-PET, and a production process for high-quality iodide single crystal materials. The iodide single crystal material of the invention having the same crystal structure as LuI3 and activated by a luminescence center RE where RE is at least one element selected from the group consisting of Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, and Yb is characterized in that a part or the whole of lutetium (Lu) in said iodide single crystal material is substituted by Y and/or Gd.

Abstract: A light emitting element has a substrate of gallium oxides and a pn-junction formed on the substrate. The substrate is of gallium oxides represented by: (AlxInyGa(1?X?Y))2O3 where 0?x?1, 0?y?1 and 0?x+y?1. The pn-junction has first conductivity type substrate, and GaN system compound semiconductor thin film of second conductivity type opposite to the first conductivity type.

Abstract: A light emitting element has a substrate of gallium oxides and a pn-junction formed on the substrate. The substrate is of gallium oxides represented by: (AlXInYGa(1-X-Y))2O3 where 0?x?1, 0?y?1 and 0?x+y?1. The pn-junction has first conductivity type substrate, and GaN system compound semiconductor thin film of second conductivity type opposite to the first conductivity type.

Abstract: A light emitting element has a substrate of gallium oxides and a pn-junction formed on the substrate. The substrate is of gallium oxides represented by: (AlXInYGa(1-X-Y))2O3 where 0?x?1, 0?y?1 and 0?x+y?1. The pn-junction has first conductivity type substrate, and GaN system compound semiconductor thin film of second conductivity type opposite to the first conductivity type.

Abstract: A method of forming a low temperature-grown buffer layer having the steps of: placing a Ga2O3 substrate in a MOCVD apparatus; providing a H2 atmosphere in the MOCVD apparatus and setting a buffer layer growth condition having an atmosphere temperature of 350° C. to 550° C.; and supplying a source gas having two or more of TMG, TMA and NH3 onto the Ga2O3 substrate in the buffer layer growth condition to form the low temperature-grown buffer layer on the Ga2O3 substrate.