Abstract: A method of synthesizing uranium dioxide crystals. The method of synthesizing includes combining a uranium-based feedstock with a mineralizer solution. The uranium-based feedstock is selected from uranium dioxide, uranium tetrafluoride, uranium tetrachloride, triuranium octoxide, and uranium trioxide. The feedstock and mineralizer solution are pressurized, and then a thermal gradient is applied thereto such that a first portion of the feedstock and the mineralizer solution is heated to a temperature that is greater than a temperature of a second portion of the feedstock and the mineralizer solution. The uranium nutrient enters the mineralizer solution from the feedstock in the first portion and uranium nutrient precipitates to spontaneously form crystals in the second portion.

Abstract: Single heterogeneous crystals are described that contain multiple regimes, adjacent regimes varying from one another with regard to function. Also disclosed is a hydrothermal epitaxial growth process that can be utilized to form the single heterogeneous crystals. The single heterogeneous crystals can exhibit enhanced performance when used as a laser gain medium as compared to previously known single crystals and multi-crystal constructs. The heterogeneous single crystal can be utilized for thin disk lasers and can minimize the thermal distortion effects at high powers. The heterogeneous crystal can also serve as an embedded waveguide.

Abstract: A method of synthesizing uranium dioxide crystals. The method of synthesizing includes combining a uranium-based feedstock with a mineralizer solution. The uranium-based feedstock is selected from uranium dioxide, uranium tetrafluoride, uranium tetrachloride, triuranium octoxide, and uranium trioxide. The feedstock and mineralizer solution are pressurized, and then a thermal gradient is applied thereto such that a first portion of the feedstock and the mineralizer solution is heated to a temperature that is greater than a temperature of a second portion of the feedstock and the mineralizer solution. The uranium nutrient enters the mineralizer solution from the feedstock in the first portion and uranium nutrient precipitates to spontaneously form crystals in the second portion.

Abstract: Single crystals are described that contain several regimes within the crystal that perform different functions related to the enhanced performance of a laser gain medium. At least one regime of the single crystals can be utilized to suppress amplified spontaneous emission and parasitic oscillation in a laser gain medium. A single crystal can include core and cladding regions, the cladding region providing amplified spontaneous emission suppression. The core region of the crystal can include as dopant one or more ions that take part in the lasing when suitably pumped. The amplified spontaneous emission suppression region can include as dopant one or more ions that can prevent additional spontaneous emission that can to depletion of the upper laser states, thus reducing laser performance including one or more ions that absorb spontaneously emitted photons and/or a higher concentration of the active lasing ions of the core.

Abstract: Single heterogeneous crystals are described that contain multiple regimes, adjacent regimes varying from one another with regard to function. Also disclosed is a hydrothermal epitaxial growth process that can be utilized to form the single heterogeneous crystals. The single heterogeneous crystals can exhibit enhanced performance when used as a laser gain medium as compared to previously known single crystals and multi-crystal constructs. The heterogeneous single crystal can be utilized for thin disk lasers and can minimize the thermal distortion effects at high powers. The heterogeneous crystal can also serve as an embedded waveguide.

Abstract: Single crystals are described that contain several regimes within the crystal that perform different functions related to the enhanced performance of a laser gain medium. At least one regime of the single crystals can be utilized to suppress amplified spontaneous emission and parasitic oscillation in a laser gain medium. A single crystal can include core and cladding regions, the cladding region providing amplified spontaneous emission suppression. The core region of the crystal can include as dopant one or more ions that take part in the lasing when suitably pumped. The amplified spontaneous emission suppression region can include as dopant one or more ions that can prevent additional spontaneous emission that can to depletion of the upper laser states, thus reducing laser performance including one or more ions that absorb spontaneously emitted photons and/or a higher concentration of the active lasing ions of the core.

Abstract: Scandium, yttrium, and lanthanide sesquioxide crystals having the formula Ln2O3, wherein Ln is selected from Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, with or without an activator ion, are made by a hydrothermal method for a variety of end-use applications.

Abstract: Scandium, yttrium, and lanthanide sesquioxide crystals having the formula Ln2O3, wherein Ln is selected from Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, with or without an activator ion, are made by a hydrothermal method for a variety of end-use applications

Abstract: Single, acentric, rhombohedral, potassium fluoroberyllium borate crystals of a size sufficient for use in a variety of laser and non-optical applications are formed by a hydrothermal method.

Abstract: Single, acentric, rhombohedral, fluoroberyllium borate crystals of a size sufficient for use in a variety of laser and non-optical applications are formed by a hydrothermal method.

Abstract: Single, acentric, hexagonal, beryllium borate crystals having the formula Sr2Be2B2O7 and of a size sufficient for use in a variety of laser and non-optical applications are formed by a hydrothermal method. Alternate structures are formed by partially substituting the strontium ion with at least one other divalent metal ion.

Abstract: The present invention is directed to lanthanide vanadate crystals having the formula LnVO4, wherein Ln is selected from La, Nd, Ce, Pr, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y, and combinations of at least two thereof, made by a hydrothermal method for a wide variety of end-use applications. The present method requires reacting a source of Ln3+ ions and a source of VO43+ ions, wherein Ln is selected from the group consisting of La, Nd, Ce, Pr, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y and combinations of at least two thereof, in an aqueous solution at a temperature of from about 350° C. to about 600° C. and at a pressure of from about 8 kpsi to about 40 kpsi, the aqueous solution comprising hydroxide ions at a concentration of from about 0.01 to about 5 molarity. Specifically, when made by the present hydrothermal method, single crystals of sufficient size for use in a variety of optical applications are readily formed.

Abstract: Acentric, tetragonal lithium borate crystals are disclosed along with a hydrothermal method for forming such crystals. The crystals possess unique optical, non-linear optical, and other photonic properties and may be formed of sufficient size to be useful in a wide variety of photonic devices. In addition, the disclosed crystals are very hard and can be used in specialty grinding applications such as for grinding optical components for deep UV applications.

Abstract: Acentric lanthanide borate crystals having the general formula LnBO3, wherein Ln is Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, or Y, are disclosed along with a hydrothermal method for forming such crystals. The crystals possess unique optical, non-linear optical, laser, electronic and other physical properties and, therefore, are useful in a wide variety of photonic devices.

Abstract: Acentric lanthanide borate crystals having the general formula LnBO3, wherein Ln is La, Ce, Pr, or Nd, are disclosed along with a hydrothermal method for forming such crystals. The crystals possess unique optical, non-linear optical, laser, electronic and other physical properties and, therefore, are useful in a wide variety of photonic devices.

Abstract: The thermoelectric properties (resistivity, thermopower and thermal conductivity) of single crystals of the low-dimensional pentatelluride materials are disclosed. The pentatellurides are well suited for use in thermoelectric devices. In general, the pentatellurides include hafnium pentatelluride and zirconium pentatelluride, which can both be substituted with selective amounts of various metals, including titanium, selenium, and antimony.