Abstract: The thermo-optic behavior of an optical path over a range of temperatures is controlled by determining a figure of merit (FoM) for the optical path and including in the path a body of NaBi(Mo1-xWxO4)2 crystalline material that enables the conditions specified by the FOM to be satisfied. The NaBi(Mo1-xWxO4)2 crystalline material is highly transparent at a wavelength of radiation propagating in the path, and has a coefficient of thermal expansion (CTE) and a refractive index n such that the CTE and dn/dT of the etalon compensate one another so as to perform frequency discrimination that is essentially temperature insensitive over the range ?T. The NaBi(Mo1-xWxO4)2 crystalline material exhibits temperature independent transmission characteristics at about room temperature and at a wavelength of about 1550 nm.

Abstract: Garnet material according to the invention exhibits a substantially rectangular magnetization loop, with .vertline.H.sub.S .vertline.>.vertline.4.pi.M.sub.S .vertline.Oe, where H.sub.S is the switching magnetic field of the loop, and 4.pi.M.sub.S is the saturation magnetization. The material exhibits "latching" behavior, and can advantageously be used in magneto-optic isolators and other magneto-optic devices. For instance, the material enables manufacture of isolators that do not contain a permanent magnet. An exemplary garnet according to the invention has nominal composition Bi.sub.0.75 Eu.sub.1.5 Ho.sub.0.75 Fe.sub.4.1 Ga.sub.0.9 O.sub.12.

Abstract: We have discovered advantageous substrates for III-V nitride semiconductors such as GaN. The substrate material is of the YbFe.sub.2 O.sub.4 or InFeO.sub.3 (ZnO).sub.n structure type and has general composition RAO.sub.3 (MO).sub.n, where R is one or more of Sc, In, Y and the lanthanides (atomic number 67-71); A is one or more of Fe(III), Ga, and Al; M is one or more of Mg, Mn, Fe(II), Co, Cu, Zn and Cd; and n is an integer.gtoreq.1, typically<9. Furthermore, the substrate material is selected to have a lattice constant that provides less than .+-.5% lattice mismatch with the III-V nitride semiconductor material that is to be deposited thereon. At least some of the substrate materials (e.g., ScMgAlO.sub.4) typically can be readily and relatively cheaply produced in single crystal form, are readily clearable on the basal plane, and do essentially not interact chemically with the III-V nitride under typical deposition conditions.

Abstract: The invention is a technique for the growth of single crystals of rare earth doped rare-earth orthosilicate crystals which may be used as the laser medium in solid-state non-semiconductor lasers. This type of laser has applications in electronics, communications, aerospace systems, and manufacturing technology where high optical output lasers are utilized. Of particular interest is the Y.sub.2-x Nd.sub.x SiO.sub.5 crystal, with x being up to 0.3, which may be efficiently pumped by a semiconductor laser, solid state non-semiconductor laser, a flashlamp or some other source of light radiation, and has been found to be operable at very high optical output. The rare-earth orthosilicate crystals are grown in accordance with this invention by a Czochralski technique from a molten mixture of constituent oxides in an inert atmosphere containing oxygen.

Abstract: High magnetic anisotropy is achieved in bismuth-iron garnet materials which comprise a significant amount of europium, samarium, or terbium. Such materials may be made in the form of epitaxial layers grown on a nonmagnetic substrate, e.g., in the manufacture of magnetic bubble devices. On account of significant Faraday rotation, such materials may also be used in magnetic-optical devices.

Abstract: Apparatus according to the invention comprises magneto-optic isolator means that utilize a novel temperature compensation scheme. The scheme involves the use of a composite magneto-optic member that comprises a first single crystal garnet layer that does not have a compensation temperature within the operating temperature range of the isolator, and further comprises a single crystal garnet layer (the "compensation point layer") that has a compensation temperature within the operating temperature range of the isolator. Exemplarily, the compensation point layer has composition (Bi.sub.0.8; Tb.sub.1.1 Gd.sub.1.1)(Fe.sub.4.6 Ga.sub.0.4)O.sub.12, and is grown on an CMZ:GGG substrate, and the first garnet layer has composition (Bi.sub.1.2 Tb.sub.1.8)(Fe.sub.4.6 Ga.sub.0.4)O.sub.12 and is grown on the compensation point layer. The novel temperature compensation scheme can result in isolators having improved extinction ratio with relatively small additional path length in the magneto-optic material.

Abstract: Certain yttrium orthosillicate phosphors doped with various rare-earths are particularly suitable for use in various display devices including cathode ray tubes. Included are single crystal phosphors which exhibit high brightness and long life under high energy excitation and conventional powder phosphors with great sensitivity.

Abstract: Light output of single crystal phosphors used on cathode ray tubes can be vastly improved by use of a microfaceted surface structure conveniently produced by use of a single crystal epitaxial layer with lattice constant slightly larger than the single crystal substrate. Such epitaxial layers are conveniently grown using substituents that increase the lattice constant compared to the single crystal substrate.

Abstract: The congruently melting composition of gadolinium scandium gallium garnet comprisesGd.sub.2.96.+-.0.03 Sc.sub.1.90.+-.0.05 Ga.sub.3.14+0.05 O.sub.12.The composition may be used as the substrate for magnetic bubble domain devices or, when doped with a suitable activator (e.g., Cr.sup.+3 or Nd.sup.+3 or both), may serve as the active medium of a solid state laser.

Abstract: The invention involves the finding that the congruent composition of any complex oxide is non-stoichiometric.

Abstract: Crystals of neodymium and praseodymium iron garnet materials have Faraday rotation which render such materials suitable for use, e.g., as antireciprocal components in optical devices and communications systems. These materials can be made by liquid-phase epitaxy on a substrate having suitable lattice parameters, deposition being carried out at relatively low melt temperatures.

Abstract: Method for producing virtually perfect massive unicrystalline gadolinium gallium garnet from a melt of gadolinium and gallium oxides containing an addition of calcium, magnesium or strontium ions.