A lasing medium having a tailored dopant concentration and a method of fabrication thereof is disclosed. The lasing medium has a single crystal having a continuous body having a selected length, wherein the crystal comprises dopant distributed along the length of the body to define a dopant concentration profile. In one embodiment, the dopant concentration profile results in a uniform heating profile. A method of fabricating a laser crystal having a tailored dopant concentration profile includes arranging a plurality of polycrystalline segments together to form an ingot, the polycrystalline segments each having dopant distributed, providing a crystal seed at a first end of the ingot, and moving a heating element along the ingot starting from the first end to a second end of the ingot, the moving heating element creating a moving molten region within the ingot while passing therealong.

A lasing medium having a tailored dopant concentration and a method of fabrication thereof is disclosed. The lasing medium has a single crystal having a continuous body having a selected length, wherein the crystal comprises dopant distributed along the length of the body to define a dopant concentration profile. In one embodiment, the dopant concentration profile results in a uniform heating profile. A method of fabricating a laser crystal having a tailored dopant concentration profile includes arranging a plurality of polycrystalline segments together to form an ingot, the polycrystalline segments each having dopant distributed, providing a crystal seed at a first end of the ingot, and moving a heating element along the ingot starting from the first end to a second end of the ingot, the moving heating element creating a moving molten region within the ingot while passing therealong.

Provided are a Ga.sub.2O.sub.3-based single crystal substrate including a Ga.sub.2O.sub.3-based single crystal which has a high resistance while preventing a lowering of crystal quality and a production method therefor. According to one embodiment of the present invention, the production method includes growing the Ga.sub.2O.sub.3-based single crystal while adding a Fe to a Ga.sub.2O.sub.3-based raw material, the Ga.sub.2O.sub.3-based single crystal (5) including the Fe at a concentration higher than that of a donor impurity mixed in the Ga.sub.2O.sub.3-based raw material, and cutting out the Ga.sub.2O.sub.3-based single crystal substrate from the Ga.sub.2O.sub.3-based single crystal (5).

Provided are a Ga.sub.2O.sub.3-based single crystal substrate including a Ga.sub.2O.sub.3-based single crystal which has a high resistance while preventing a lowering of crystal quality and a production method therefor. According to one embodiment of the present invention, the production method includes growing the Ga.sub.2O.sub.3-based single crystal while adding a Fe to a Ga.sub.2O.sub.3-based raw material, the Ga.sub.2O.sub.3-based single crystal (5) including the Fe at a concentration higher than that of a donor impurity mixed in the Ga.sub.2O.sub.3-based raw material, and cutting out the Ga.sub.2O.sub.3-based single crystal substrate from the Ga.sub.2O.sub.3-based single crystal (5).

Using processes disclosed herein, materials and structures are created and used. For example, processes can include melting boron nitride or amorphous carbon into an undercooled state followed by quenching. Exemplary new materials disclosed herein can be ferromagnetic and/or harder than diamond. Materials disclosed herein may include dopants in concentrations exceeding thermodynamic solubility limits. A novel phase of solid carbon has structure different than diamond and graphite.

Using processes disclosed herein, materials and structures are created and used. For example, processes can include melting boron nitride or amorphous carbon into an undercooled state followed by quenching. Exemplary new materials disclosed herein can be ferromagnetic and/or harder than diamond. Materials disclosed herein may include dopants in concentrations exceeding thermodynamic solubility limits. A novel phase of solid carbon has structure different than diamond and graphite.

Using processes disclosed herein, materials and structures are created and used. For example, processes can include melting boron nitride or amorphous carbon into an undercooled state followed by quenching. Exemplary new materials disclosed herein can be ferromagnetic and/or harder than diamond. Materials disclosed herein may include dopants in concentrations exceeding thermodynamic solubility limits. A novel phase of solid carbon has structure different than diamond and graphite.

A single-crystal production equipment includes a transparent quartz tube, in which a seed crystal is placed; a powder raw material supply apparatus, which is arranged above the transparent quartz tube and supplies a powder raw material onto the seed crystal placed in the transparent quartz tube; and an infrared ray irradiation apparatus, which is arranged outside the transparent quartz tube and applies an infrared ray to the upper surface of the seed crystal placed in the transparent quartz tube as well as the powder raw material supplied into the transparent quartz tube by the powder raw material supply apparatus. The infrared ray melts the upper surface of the seed crystal and the powder raw material and subsequently the resulting melt solidifies on the seed crystal to provide a single crystal.

A single-crystal production equipment includes a transparent quartz tube, in which a seed crystal is placed; a powder raw material supply apparatus, which is arranged above the transparent quartz tube and supplies a powder raw material onto the seed crystal placed in the transparent quartz tube; and an infrared ray irradiation apparatus, which is arranged outside the transparent quartz tube and applies an infrared ray to the upper surface of the seed crystal placed in the transparent quartz tube as well as the powder raw material supplied into the transparent quartz tube by the powder raw material supply apparatus. The infrared ray melts the upper surface of the seed crystal and the powder raw material and subsequently the resulting melt solidifies on the seed crystal to provide a single crystal.

Provided are: a method for manufacturing a highly pure silicon by unidirectional solidification of molten silicon, that can inexpensively and industrially easily manufacture highly pure silicon that has a low oxygen concentration and low carbon concentration and is suitable for applications such as manufacturing solar cells; highly pure silicon obtained by this method; and silicon raw material for manufacturing highly pure silicon. A method for manufacturing highly pure silicon using molten silicon containing 100 to 1000 ppmw of carbon and 0.5 to 2000 ppmw of germanium as the raw material when manufacturing highly pure silicon by unidirectionally solidifying molten silicon raw material in a casting container, the highly pure silicon obtained by this method, and the silicon raw material for manufacturing the highly pure silicon.