Abstract: A thick film bismuth doped rare earth iron garnet greater than 50 ?m in thickness with a growth-induced uniaxial anisotropy less than zero, such that all the magnetic domains in the film have their magnetization vectors in the plane of the film. A preferred embodiment comprises a film of composition Bi1.13Gd1.36Lu0.51Fe4.55Ga0.45O12. Films with such anisotropy solve the problem of devices and sensors that require a continuously varying Faraday rotation without the effective insertion losses that are inherent to discrete perpendicular domains. A similar effect can be achieved with a film of perpendicular domains by launching the light in the plane of the thick film in a non-waveguiding mode as opposed to the conventional perpendicular direction.

Abstract: Faraday rotator garnet thick films have improved specific Faraday rotations without requiring a bias magnet. Films of nominal composition BiX(EuZHo1-Z)3-XFe5-YGaYO12 are grown lattice matched to available {Gd2.68Ca0.32}[Ga1.04Mg0.32Zr0.64](Ga3)O12 substrates. The film is prepared with Z ≦0.45, which allows higher concentrations of Bi to be included in the film than prior compositions. The increased amount of Bi results in a higher specific Faraday rotations for the film. For devices such as non-reciprocal optoelectronic devices that require 45-degree rotators, the increased specific Faraday rotation results in the use of thinner films of reduced path length as well as increased crystal growth yields.

Abstract: Polarization compensators and devices and systems incorporating them including polarization rotator means that employ novel polarization compensation means. The novel polarization compensator means employs the use of a variable retarder means with retardation dependent on environmental, system or operating requirements coupled with a second retarder means of substantially 90 degrees of retardation at the center specification conditions of operation. The polarization compensator may be part of either a reciprocal or a non-reciprocal device also having Faraday rotator means with specific dependence on temperature and wavelength. To improve performance significantly, temperature and/or wavelength dependence of the variable retarder of the invention is adjusted to be between about 1 and 3 times and preferably between about 1.5 and 2.5 times) the temperature and/or wavelength dependence of the Faraday rotator.

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: 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: A sol-gel procedure is described for making display devices with luminescent films. The procedure typically involves hydrolysis and polymerization of an organometallic compound together with selected luminescent ions, and coating of a substrate and then heat treatment to form a polycrystalline layer. The procedure is particularly useful for making cathode ray tubes, expecially those for high power operation because of the excellent luminescence characteristics obtained, good thermal contact from the luminescent layer to faceplate and low cost of the procedure. Also described are the devices obtained which exhibit a layer of complex oxide with network structure much like the corresponding bulk compound.

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: 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: An optical isolator is disclosed which comprises a Faraday rotator disposed between a pair of polarization selective elements (e.g., linear polarizers, birefringent wedges, birefringent plates, etc.). Improvement in isolation stability as a function of variations in temperature and/or signal wavelength are achieved in accordance with the teachings of the present invention by utilizing a Faraday device with a rotation .theta. less than the conventional 45.degree.. A linear reduction in .theta., while resulting in a some signal loss, provides a linear increase in both temperature and wavelength stability.