Abstract: An apparatus useful in immunoassay of a fluid, light is directed to an optical sensor wherein the light is transmitted to a replaceable optical device that is responsive to index of refraction in a sensing region thereof that is exposed to the fluid. One portion of the light is transmitted via a compensation path that includes the sensing region to a first detector. Another portion of the light is transmitted via a sensing path that includes the sensing region to another detector. In one embodiment a ratioing device receives an output from each detector and provides a signal responsive to the ratio of the outputs. The replaceable optical device typically comprises a pair of channel waveguides in directional coupling arrangement, or a pair of channel waveguides in an interferometer arrangement, or a ridge waveguide having a curved or serpentine path configured so that nonspecific sensing effects are compensated.

Abstract: Apparatus for modulation of optical signals at millimeter-wave frequencies comprises a thin elongate dielectric slab (1) of lithium niobate to partially confine and guide therein a polarized electrical signal (8) at millimeter-wave frequencies; a thinner optical waveguide (3) of lithium niobate with titanium diffused therein to substantially confine and guide therein an optical signal (9), having at least one elongate surface adjacent to an elongate surface of the dielectric slab (1); an optical grating (5) of arsenic trisulfide for directing a polarized optical signal (9) into the waveguide (3) to propagate in a lengthwise direction therein; an optical grating (7) of arsenic trisulfide for directing the optical signal (9) out of the waveguide (3) after it has traversed a predetermined distance therein; and a metallic waveguide (2) for directing an electrical signal (8) into the dielectric slab (1) in the same direction as that of the optical signal (9) in the waveguide (3), and at a center frequency such tha

Abstract: A Luneburg lens is provided on a diffused waveguide having a graded index profile and has a contour computed in accordance with the graded index in the waveguide.

Abstract: On-line inspection of electric characteristics of a semiconductor device can be achieved during a step of bonding a lead wire to a chip surface of the semiconductor device in the process of fabricating an electronic component, by the use of a circuit arrangement formed between a lead wire fed from a bonder and connectors serving as electric terminals when the chip is mounted thereon to be made into an electronic component, and by the application of electric power thereto.

Abstract: A method for forming a Luneburg lens having a predetermined focal length on an optical waveguide includes fabricating the lens on a waveguide from a photorefractive material and then exposing the lens to energy radiation, particularly ultra violet light, to thereby adjust the refractive index until the predetermined focal length is established.

Abstract: Methods and apparatus for directing a beam of optical radiation toward a selected location and modulating the intensity thereof at the location by directing the beam over a path that includes a Bragg grating, and selectively modifying the angle between the direction at which the beam enters the Bragg grating and a direction of Bragg incidence of the grating by applying an electric or acoustic field to change the index of refraction in a portion of the path. An electric field may be applied either by interdigital electrodes at the grating, to change the Bragg angle thereof, or by electrodes at different angles across an earlier portion of the path, to change the direction at which the beam enters the grating. An acoustic field may be applied in an analogous manner. Useful for modulating and switching in planar wave guides and bulk material.