Abstract: A superconducting electronic circuit device, useful when impedance matching is desired, especially suited to microwave frequencies, consisting of a thin dielectric layer with superconducting layers on both sides. A superconductor such as Yttrium Barium Copper Oxide (YBCO) is formed on a first substrate such as lanthanum aluminate. A protective layer like gold is deposited on the YBCO and a second carrier substrate is bonded to the protected YBCO. The first substrate is then thinned into a thin dielectric film and a second layer of superconductor is epitaxially grown thereon to create the desired circuits.

Abstract: A Seebeck effect thermoelectric cooler, operative at cryogenic temperatures, in which two materials having different Seebeck coefficients are in electrical contact so that current flow thereacross cools the junction. One or both of the materials comprise a metal-insulator transition material characterized by doping, alloying, or other means to be just slightly metallic so that electrical resistance becomes lower at lower temperatures, but the Seebeck coefficient does not decline at lower temperatures, as would be the case if the material were allowed to become fully metal-like.

Abstract: A method and apparatus for measuring nonreciprocal optical effects contemplates directing two circularly polarized optical beams having a known phase relation to each other at a sample, and detecting the difference in phase between the two beams after they have encountered the sample. In a transmission measurement the two circularly polarized beams have the same handedness, but pass through the sample in opposite directions. In a reflection measurement, the two circularly polarized beams have opposite handedness, but encounter the sample in the same direction. In a particular embodiment of the invention a linearly polarized beam is introduced into a Sagnac interferometer and split into two linearly polarized beams which are ultimately recombined.

Abstract: A superconducting Josephson junction is created in high T.sub.c superconducting film, with a bridge connecting two superconducting banks, by subjecting the bridge to a tunneling electron current from a sharp electrode close to the bridge. The tunneling current alters the structure over atomic dimensions to create a weak link of length comparable to high T.sub.c coherence lengths so as to permit phase coherent Cooper pair current flow across the weak link.

Abstract: Novel superconducting oxide compositions of the formulas (YBa.sub.2 Cu.sub.3.25).sub.a O.sub.z and Y.sub.2 Ba.sub.4 Cu.sub.8 O.sub.20-x (248) are provided which can have an ordered defect structure stacked on one axis. MiThis invention was made with Government support under contracts DMR-8616055 awarded by the National Science Foundation and F49620-88C-0004 awarded by the United States Air Force. The Government has certain rights in this invention.

Abstract: A superconducting transition edge bolometer is constructed using high critical temperature conducting films by stabilizing a substrate of magnesium oxide or sapphire with a silicon base that is bonded to the substrate using a thermally conductive bonding layer. The base is etched away in the region of the desired radiation detecting portion of the superconductor establishing a controlled thermal connection between the detecting portion and the base which base serves as a thermal bath for the bolometer.

Abstract: A method of forming a superconducting YBa.sub.2 Cu.sub.3 O.sub.7-x thin film with selected crystal orientation is described which comprises the steps of sputtering simultaneously Y, Ba and Cu onto the surface of a substrate, introducing oxygen at said surface during deposition, controlling the stoichiometry of the elements Y, Ba or both richer or poorer than the 1:2:3 stoichiometry within a few atom percent and followed by annealing to selectively grow an a-axis or a c-axis oriented film of YBa.sub.2 Cu.sub.3 O.sub.7-x.