Abstract: A spinel composition of the invention includes a monocrystalline lattice having a formula Mg1-w?wAlx-y?yOz, where w is greater than 0 and less than 1, x is greater than 2 and less than about 8, y is less than x, z is equal to or greater than about 4 and equal to or less than about 13, ? is a divalent cationic element having an ionic radius greater than divalent magnesium, and ? is a trivalent cationic element having an ionic radius greater than trivalent aluminum. The monocrystalline lattice has tetrahedral and octahedral positions, and most of the magnesium and ? occupy tetrahedral positions. In one embodiment, the molar ratio of aluminum to the amount of magnesium, ? and ? can be controlled during growth of the monocrystalline lattice thereby forming a spinel substrate suitable for heteroepitaxial growth of III-V materials. A method of the invention, includes forming a monocrystalline lattice of a spinel composition.

Abstract: A saturable absorber Q-switch includes a monocrystalline lattice having the formula Mg1-xCoxAlyOz where x is greater than 0 and less than 1, y is greater than 2 and less than about 8, and z is between about 4 and 13. The lattice has tetrahedral and octahedral positions, and most of the magnesium and cobalt occupy tetrahedral positions. In one embodiment, the molar ratio of aluminum to the combined amount of magnesium and cobalt in the monocrystalline lattice can be controlled during growth of the monocrystalline lattice to thereby form a saturable absorber Q-switch that exhibits a 4T1 spectrum for the cobalt ion of at least about 1544 ?m.

Abstract: A single crystal ceramic material for optical and optoelectronic applications is d, including a single crystal spinel having a general formula aAD·bE2D3, wherein A is selected from the group consisting of Mg, Ca, Zn, Mn, Ba, Sr, Cd, Fe, and combinations thereof, E is selected from the group consisting Al, In, Cr, Sc, Lu, Fe, and combinations thereof, and D is selected from the group consisting O, S, Se, and combinations thereof.

Abstract: A spinel composition of the invention includes a monocrystalline lattice having a formula Mg1−w&agr;wAlx−y&bgr;yOz, where w is greater than 0 and less than 1, x is greater than 2 and less than about 8, y is less than x, z is equal to or greater than about 4 and equal to or less than about 13, &agr; is a divalent cationic element having an ionic radius greater than divalent magnesium, and &bgr; is a trivalent cationic element having an ionic radius greater than trivalent aluminum. The monocrystalline lattice has tetrahedral and octahedral positions, and most of the magnesium and &agr; occupy tetrahedral positions. In one embodiment, the molar ratio of aluminum to the amount of magnesium, &agr; and &bgr; can be controlled during growth of the monocrystalline lattice thereby forming a spinel substrate suitable for heteroepitaxial growth of III-V materials. A method of the invention, includes forming a monocrystalline lattice of a spinel composition.

Abstract: A saturable absorber Q-switch includes a monocrystalline lattice having the formula Mg1-xCoxAlyOz where x is greater than 0 and less than 1, y is greater than 2 and less than about 8, and z is between about 4 and 13. The lattice has tetrahedral and octahedral positions, and most of the magnesium and cobalt occupy tetrahedral positions. In one embodiment, the molar ratio of aluminum to the combined amount of magnesium and cobalt in the monocrystalline lattice can be controlled during growth of the monocrystalline lattice to thereby form a saturable absorber Q-switch that exhibits a 4T1 spectrum for the cobalt ion of at least about 1544 &mgr;m.

Abstract: A room temperature solid-state laser is provided. A laser crystal is disposed in a laser cavity. The laser crystal has a LuAG host material doped with a concentration of about 0.35% Ho ions, about 5.57% Tm ions and at least about 1.01% Cr ions. A broadband energizing source such as a flashlamp is disposed transversely to the laser crystal to energize the Ho ions, Tm ions and Cr ions.

Abstract: The Figure of Merit of titanium-doped oxide crystals suitable for use as a tunable laser is enhanced by treating the article at a temperature of about 50.degree. C. to 80.degree. C. below the melting point of the crystal in an atmosphere containing at least about 20 volume percent hydrogen.

Abstract: The Figure of Merit of titanium-doped sapphire crystal article suitable for use as a tunable laser is enhanced by treating the article at a temperature of about 1750.degree. C. to 2025.degree. C. in an atmosphere containing at least about 20 volume percent hydrogen.

Abstract: Controlled growth atmosphere process for titanium doped tunable laser material to enhance lasing efficiency using carbon monoxide during melt formation.

Abstract: Annealing process for titanium doped sapphire tunable laser material to enhance lasing efficiency. The process comprises (I) heating the material in a vacuum of at least 1.times.10.sup.-6 torr at a temperature in the range of about 1850.degree. to 2,000.degree. C. for at least 48 hours and (II) cooling the material from its temperature in said range to 1500.degree. C. at a rate not exceeding 2.degree. C. per minute.

Abstract: Magnetic film-substrate composites of enhanced quality are provided by rotating a garnet substrate immersed in a melt of magnetic film material to obtain a growth of magnetic film having uniaxial anistropy on the substrate normal to the substrate surface and maintaining the immersed substrate stationary in the melt after a desired film growth has been achieved to effect enhancement of the anisotropy constant of the film.

Abstract: Congruently melting compositions of gallium garnets containing lanthanum are provided in which trivalent indium is partially substituted for gallium. The lanthanum indium gallium garnets have larger lattice parameters than other rare earth gallium garnets. The lanthanum indium gallium garnets of the invention are represented by the formulaLa.sub.a In.sub.b Ga.sub.c O.sub.12where "a" ranges from greater than about 3.24 to less than 3.32, "b" ranges from greater than about 1.84 to less than about 2.24 and "c" ranges from greater than about 2.48 to less than about 2.88, the total of "a" plus "b" plus "c" being 8. The garnets of the invention are useful as single crystal substrates for supporting magneto-optic and magnetic garnet thin films having large lattice parameters approaching 13 A.