Abstract: A self-biasing, non-magnetic giant magnetoresistive sensor having a Corbino-disk geometry constructed from a thin film of e.g., doped, Mercury Cadmium Telluride (MCT) Hg.sub.1-x Cd.sub.x Te exhibiting anomalously large Giant Magnetresistance (GMR) and zero field offset. In one embodiment, the sensor has a silicon substrate, a layer of doped, inhomogeneous MCT, and electrodes attached to the inhomogeneous layer. Alternatively, a buffer layer of, e.g., CdTe may overlay the substrate. In another embodiment, the sensor has a silicon substrate, a layer of doped, homogeneous MCT, and electrodes attached to the doped homogeneous MCT. Alternatively, a buffer layer of, e.g., CdTe may overlay the substrate as well. With constructed in as either of these embodiments, highly doped Corbino devices may show a significant zero-field offset in the GMR which results in a built-in bias field as high as 1500 G at T=300 K.

Abstract: The low-field magnetoresistance of a high carrier mobility semiconductor with inhomogeneities which are more conducting than the surrounding semiconductor material matrix is significantly enhanced compared to the magnetoresistance of the homogeneous material. The enhancement results from a magnetic field induced geometric effect in which current is expelled from the conducting inhomogeneity. The enhanced giant magnetoresistance is demonstrated at low field in (near) zero-band-gap material, such as Hg.sub.1-x Cd.sub.x Te(x.about.0.1). The effect is applied to the fabrication of magnetic read head sensors such as Corbino disc, bar magnetoresistance sensors and thin film sensors.

Abstract: A non-magnetic magnetoresistive head for reading a magnetic pattern stored as domains in tracks on a storage device uses as the sensor a wafer of a high electron mobility non-magnetic semiconductor, such as indium antimonide or mercury-cadmium telluride, which includes an electrode configuration that includes an inner stripe electrode and an outer rectangular electrode surrounding the inner electrode. The wafer is supported so that the plane of the wafer is parallel to the disk and perpendicular to the magnetic field being sensed.

Abstract: A self-biasing, non-magnetic giant magnetoresistive sensor constructed from a thin film of inhomogeneous magnetoresistive material showing Giant Magnetresistance (GMR) at T=300.degree. K., e.g., Mercury Cadmium Telluride. In one embodiment, the sensor has a silicon substrate, a layer of inhomogeneous magnetoresistive material, e.g., Hg.sub.l-x Cd.sub.x Te, and electrodes attached to the non-homogeneous magnetoresistive layer. Alternatively, a buffer layer of, e.g., CdTe may overlay the substrate. In another embodiment, the sensor is an active element of a read/write head, particularly well suited for reading information signals stored in a magnetic medium.

Abstract: A magnetic sensor for use in a reading head for a magnetic disk is formed by depositing a plurality of planar superimposed layers of metals and semiconductors and using for the active element a planar structure formed orthogonal to the superimposed layers by their edges. Specifically, the edges of the superimposed layer form on the orthogonal planar surface a Corbino-disk structure in which conductive regions form inner and outer electrodes about an annular semiconductive region with high magnetoresistance, such as is provided by cadmium mercury telluride or indium antimonide.

Abstract: A sensor for use in read/writing the magnetic pattern stored in a magnetic storage disk uses a Corbino structure comprising inner and outer electrodes enclosing a magnetoresistive element. The sensor is formed at the front surface of a stack of superposed layers of which the first and fifth are of a high resistivity semiconductive material, the second and fourth are of a magnetoresistive material and the third of a metal or composite structure. The second and fourth layers form a loop around the third layer, the first and fifth form a loop around the second and fourth layers. A dopant is diffused into the front surface of the stack to convert edge portions of the first and fifth layers to low resistivity to form a conductive loop that serves as the outer electrode of the Corbino disk, the third electrode serving as the inner electrode.

Abstract: A superlattice comprising alternating layers of undoped GaAs and silicon doped Al.sub.0.3 Ga.sub.0.7 As is used as a magnetoresistor for measuring magnet fields in excess of one Tesla. The magnetic field to be measured is passed vertically through the superlattice and current from a source of constant current is flowed vertically through the resulting superlattice and the voltage drop across the superlattice is measured to provide an indication of the strength of the magnetic field.

Abstract: An ophthalmic laser surgery system includes a slit lamp (14) with an illuminator (16) and a biomicroscope (26). The high power laser (34) delivers a laser beam (36) which is mixed with the output from a lower power laser (38) with a dichroic mirror (54). The output of the dichroic mirror (54) is input to the harmonic generator (60) to generate harmonics thereof. The output of the harmonic generator (60) is optically directed to move along the rotational axis through rotational supports (22) and (30). The laser beam is then directed by mirrors (72) and (80) to a focusing lens (90) and a filter (92) to a dielectric mirror (94). The dielectric mirror (94) mixes the illumination from the slit lamp (14) with the laser beam for delivery to the eye (12). A micromanipulator (102) adjusts the position of the dielectric mirror (94). A control circuit (104) controls the operation of the laser (34).

Abstract: A binocular endoscope for diagnostic work, medical treatment and surgical procedures providing depth perception in the image of an object viewed. Image transmittal from the viewed object to the viewing station is through a non-distorting, high resolution, optical system utilizing long path length lens means. Selectable field viewing through 360.degree. of continuous rotation, with preservation with image conformity, is achieved through the use of a dove prism in combination with mechanical linkage to compensate for rotation effects. The apparatus also includes field illumination means, fluid input and exhaust channels and a manipulable surgical element.