Methods and devices for detecting incident radiation are provided. The methods and devices use high quality single-crystals of photoactive semiconductor compounds in combination with metal anodes and metal cathodes that provide for enhanced photodetector performance.

The invention relates to a method for growing a bulk single crystal, wherein the method comprises the steps of inserting a starting material into a crucible, melting the starting material in the crucible by heating the starting material, arranging a thermal insulation lid at a distance above a melt surface of said melt such that at least a central part of the melt surface is covered by the lid, and growing the bulk single crystal from the melt by controllably cooling the melt with the thermal insulation lid arranged above the melt surface.

A process for directional solidification of a cast part comprises energizing a primary inductive coil coupled to a chamber having a mold containing a material; energizing a primary inductive coil within the chamber to heat the mold via radiation from a susceptor, wherein the resultant electromagnetic field partially leaks through the susceptor coupled to the chamber between the primary inductive coil and the mold; determining a magnetic flux profile of the electromagnetic field; sensing a magnetic flux leakage past the susceptor within the chamber; generating a control field from a secondary compensation coil coupled to the chamber, wherein the control field controls the magnetic flux experienced by the cast part; and casting the material within the mold under the controlled degree of flux leakage.

Produced is a large single crystal with no crystal grain boundary, which is a high-quality single crystal that has a uniform composition in both the vertical and horizontal directions at an optimum dopant concentration and contains only a small number of negative crystals and exsolution lamellae. A single-crystal production equipment includes at least: a quartz crucible in which a seed crystal is placed on its bottom; a powder raw material supply apparatus which supplies a powder raw material into the quartz crucible; and an infrared ray irradiation apparatus which applies an infrared ray to the powder raw material supplied into the quartz crucible from the powder raw material supply apparatus.

In a gallium arsenide crystal body, an etching pit density of the gallium arsenide crystal body is more than or equal to 10 cm.sup.2 and less than or equal to 10000 cm.sup.2, and an oxygen concentration of the gallium arsenide crystal body is less than 7.010.sup.15 atoms.Math.cm.sup.3. In a gallium arsenide crystal substrate, an etching pit density of the gallium arsenide crystal substrate is more than or equal to 10 cm.sup.2 and less than or equal to 10000 cm.sup.2, and an oxygen concentration of the gallium arsenide crystal substrate is less than 7.010.sup.15 atoms.Math.cm.sup.3.

The present disclosure discloses a shell mold chamber, a foundry furnace and a method for casting single crystal, fine crystal and non-crystal, which employ the technique of asynchronous-curving supercooling, and belongs to the technical field of precise casting apparatuses. Such a three-function foundry furnace includes a heating coil winding, a first thermal-shield assembly, a first superconducting coil, a second thermal-shield assembly and a second superconducting coil; and the first superconducting coil is provided at an inside of the first thermal-shield assembly, and the second superconducting coil is provided at an inside of the second thermal-shield assembly; and directions of a magnetic field generated by the first superconducting coil and a magnetic field generated by the second superconducting coil are opposite; and the first superconducting coil and the heating coil winding form a forward-directional static-magnetic-field heating zone, and the second superconducting coil forms a reverse-directional static-magnetic-field zone.

An induction furnace assembly comprising a chamber having a mold; a primary inductive coil coupled to the chamber; a layered susceptor comprising at least two layers of magnetic field attenuating material surrounding the chamber between the primary inductive coil and the mold to nullify the electromagnetic field in the hot zone of the furnace chamber.

A method of making a component includes: depositing a metallic powder on a workplane; directing a beam from a directed energy source to fuse the powder in a pattern corresponding to a cross-sectional layer of the component; repeating in a cycle the steps of depositing and fusing to build up the component in a layer-by layer fashion; and during the cycle of depositing and melting, using an external heat control apparatus separate from the directed energy source to maintain a predetermined temperature profile of the component, such that the resulting component has a directionally-solidified or single-crystal microstructure.

A compound strontium fluoroborate, nonlinear optical crystal of strontium fluoroborate, preparation method thereof; the chemical formula of the compound is SrB5O7F3, its molecular weight is 310.67, and it is prepared by solid-state reaction; the chemical formula of the crystal is SrB5O7F3, its molecular weight is 310.67, the crystal is of the orthorhombic series, the space group is Ccm21, and the crystal cell parameters are=10.016(6) , b=8.654(6)(4) , c=8.103(5) , Z=4, and V=702.4(8) 3. A SrB5O7F3 nonlinear optical crystal has uses in the preparation of a harmonic light output when doubling, tripling, quadrupling, quintupling, or sextupling the frequency of a 1064-nm fundamental-frequency light outputted by a Nd:YAG laser, or the generation of a deep-ultraviolet frequency doubling light output lower than 200 nm, or in the preparation of a frequency multiplier, upper or lower frequency converter, or an optical parametric oscillator.

A process for directional solidification of a cast part comprises energizing a primary inductive coil coupled to a chamber having a mold containing a material; energizing a primary inductive coil within the chamber to heat the mold via radiation from a susceptor, wherein the resultant electromagnetic field partially leaks through the susceptor coupled to the chamber between the primary inductive coil and the mold; determining a magnetic flux profile of the electromagnetic field; sensing a magnetic flux leakage past the susceptor within the chamber; generating a control field from a secondary compensation coil coupled to the chamber, wherein the control field controls the magnetic flux experienced by the cast part; and casting the material within the mold under the controlled degree of flux leakage.