Hydrothermal Crystal Growth of Oxides for Optical Applications

There is great interest in obtaining coherent radiation in all regions of the optical spectrum. This dissertation explores the hydrothermal growth of crystals that function in two regions currently inaccessible by solid state devices. The first gap exists in the deep-UV region, particularly below 200 nm. Some materials such as LBO and BBO can generate coherent light at wavelengths as low as 205 nm. The growth of these materials was explored to investigate the feasibility of the hydrothermal method as a new technique for growing these crystals. Particular attention was paid to the descriptive chemistry surrounding these systems, and several novel structures were elucidated. The study was also extended to the growth of materials that could be used for the generation of coherent light as low as 155 nm. Novel synthetic schemes for Sr2Be2B2O7 and KBe2BO3F2 were developed and the growth of large crystals was explored. An extensive study of the structures, properties and crystal growth of related compounds, RbBe2BO3F2 and CsBe2BO3F2, was also undertaken. Optimization of a number of parameters within this family of compounds led to the hydrothermal growth of large, high quality single crystal at rates suitable for large-scale growth. The second gap in technology is in the area of high average power solid state lasers emitting in the 1 μm and eye-safe (\u3e1.5 μm) regions. A hydrothermal technique was developed to grow high quality crystals of Sc2O3 and Sc2O3 doped with suitable lanthanide activator ions. Preliminary spectroscopic studies were performed and large crystals were again grown at rates suitable for commercial production. The synthesis of ultra-high purity Ln2O3 (Ln = Sc, Y, La-Lu) nanoparticles was also explored to advance the development of ceramic-based solid state lasers. Crystal growth is a complex task involving a great number of intricacies that must be understood and balanced. This dissertation has advanced the art and science of growing crystals, and documented the development of large, high quality crystals of advanced optical materials The materials and hydrothermal crystal growth techniques developed over the course of this work represent important progress toward controlling the optical spectrum

Hydrothermal Growth of Heterogenous Single Crystals Exhibiting Amplified Spontaneous Emission Suppression

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

Single crystals with internal doping with laser ions prepared by a hydrothermal method

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

Hydrothermal Method for Preparing Large Single Crystals of Scandium, Yttrium, and Lanthanide Sesquioxides

Scandium, yttrium, and lanthanide sesquioxide crystals having the formula Ln.sub.2O.sub.3, 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

Method for forming heterogeneous single garnet based crystals for passive Q-switched lasers and microlasers

Disclosed are heterogeneous crystals for use in a laser cavity and methods of forming the crystals. A crystal can be a monolithic crystal containing a garnet-based activator region and a garnet-based Q-switch. Disclosed methods include hydrothermal growth techniques for the growth of differing epitaxial layers on a host. A YAG host material can be doped in one region with a suitable activator ion for lasing and can be formed with another region that is doped with a saturable absorber to form the Q-switch. Regions can be formed with controlled thickness in conjunction. Following formation, a heterogeneous crystal can be cut, polished and coated with mirror films at each end for use in a laser cavity to provide short pulses of high power emissions using high frequency pulse modes

Heterogeneous single vanadate based crystals for Q-switched lasers and microlasers and method for forming same

Disclosed are heterogeneous crystals for use in a laser cavity and methods of forming the crystals. A crystal can be a monolithic crystal containing a vanadate-based activator region and a vanadate-based Q-switch. Disclosed methods include hydrothermal growth techniques for the growth of differing layers on a host. A YVO4 host material can be doped in one region with a suitable active lasing ion and can be formed with another region that is doped with a saturable absorber. Regions can be formed with controlled thickness. Following formation, a heterogeneous crystal can be cut, polished and coated with mirror films at each end for use in a laser cavity to provide short pulses of high power emissions using high frequency pulse modes

Halogen Bonding in Nitrogen and Iodine Compounds to Form Novel Cocrystals

https://tigerprints.clemson.edu/csrp/1019/thumbnail.jp

Integration of triboluminescent EuD4TEA crystals to transparent polymers: Impact sensor application

Lanthanide-based organometallic materials are well-known candidate triboluminescent (TL) materials that can show bright emission when a mechanical force is applied. These materials are usually in the form of crystalline powders, and it is often useful to integrate these samples into a polymer matrix in order to achieve processability, enabling coating from a solution/molten state or fabrication as a complex-shaped matrix. In this work, micrometer-sized europium tetrakis (dibenzoylmethide) triethylammonium (EuD4TEA) crystals were synthesized and integrated with various transparent polymers (PMMA, PS, PVDF, and PU) using two approaches: (i) blending and (ii) surface impregnation. In the former method, the crystalline particles were molecularly dissolved; therefore, a TL response cannot be achieved. More than 10 wt % TL crystals in the composite is needed to obtain TL signals. However, TL signal was achieved at 2.5 wt % when a composite was prepared by the latter approach. TL intensity shows exponential decay with consecutive mechanical action. The TL emission of PU-based surface impregnated composite expires with long-lived emission, and maximum TL response with respect to applied force was measured between 2.45 and 42.0 N.Scientific and Technological Research Council of Turkey (TUBITAK KBAG-114Z292

Hydrothermal Growth of Heterogeneous Single Crystals for Solid State Laser Applications

Disclosed are heterogeneous crystals for use in a laser cavity and methods of forming the crystals. A crystal can be a monolithic crystal containing regions that are based upon the same host material but differ from one another according to some material feature such that they can perform various functions related to lasing. Disclosed methods include hydrothermal growth techniques for the growth of differing epitaxial layers on a host. A host material can be doped in one region with a suitable active lasing ion and can be formed with another region that is undoped and can act as an endcap, a waveguide cladding layer, or a substrate to provide strength and/or contact to a heat sink. Regions can be formed with controlled thickness in conjunction. Following formation, a heterogeneous crystal can be cut, polished and coated with mirror films at each end for use in a laser cavity