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).

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.

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.

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.

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.