Abstract: A Sagnac rotation-sensing interferometer with a fiber-optic loop for providing a closed optical path in which counter-propagating light beams are phase shifted due to the Sagnac effect and with an otical coupler for splitting an input beam into the counter-propagating light beams in the fiber-optic loop and for providing for interference between the output beams of the fiber-optic loop. The optical coupler includes a (3.times.3) coupler with two first output waveguides symmetrically disposed about an input waveguide for splitting the input beam into equal components and a (2.times.2) coupler with two second output waveguides adjacently disposed for providing interference between the output beams. The second output waveguides of the (2.times.2) coupler couple the first otput waveguides of the (3.times.3) coupler to the end of the fiber-optic loop.

Abstract: A Sagnac rotation sensing interferometer disposed on a rotating platform for use as a gyrsocope comprising a closed optical light path and a beam splitter for splitting an input light beam into two beams directed to transverse the closed optical path in opposite directions wherein the beam splitter is composed of a directional coupler with three input ports and three output ports. The first of the three input ports receives optical input and the second and third of the input ports are disposed symmetrically with respect to the first input port. Optical output from two output ports corresponding to the second and third input ports are directed to both ends of the closed optical fiber light path. A gyroscope according to this arrangement provides light output from the beam splitter which operates automatically near quadrature without a nonreciprocal .pi./2 phase bias applied in the fiber loop as required in conventional optical fiber gyroscopes.

Abstract: A Sagnac rotation sensing interferometer disposed on a rotating platform use as a gyroscope comprising a wound optical fiber light path, a beam splitter for splitting a light beam into two beams directed to traverse the optical path in opposite directions, a light source circuit for generating a light beam which is switched between two wavelengths at a switching or modulation frequency substantially higher than the speed of change of the phase due to rotation, and a detector for extracting a signal from the recombined beam interference pattern at the wavelength modulation frequency, this signal being proportional to the phase shift caused by rotation.

Abstract: A single-mode or multimode, optical, fiber-to-fiber coupler which couples such fibers together so that an optical beam guided by one fiber is coupled to the other fiber through evanescent field coupling. In coupling fibers together, the plastic coating is removed along a desired length of each fiber. The fibers are twisted or braided together and cladding is etched to a desired diameter in a suitable housing. After etching, the etchant is drained and the fibers and inside of the housing are cleaned by any suitable cleaning solution. Subsequent to cleaning, the housing is filled with a solution or material which has an index of refraction which is less than that of the core. It has been determined that coupling efficiency can be controlled simply by adusting the tension of the coupling fibers.

Abstract: An electrooptical waveguide assembly comprising a plurality of waveguide blocks wherein each of said waveguide blocks has a waveguiding region and a substrate region supporting the waveguiding region, the waveguide blocks being connected in a row to have successive face-to-face contact in such a way that said waveguiding regions are aligned for continuous optical-beam transfer from one of said waveguide blocks to the next, and the crystallographic orientations of any two neighboring waveguide blocks are different from each other so that two orthogonal propagating modes being guided through said waveguiding regions experience a balanced electrooptic effect from electric fields applied to the waveguide.

Abstract: An electrooptical waveguide switching device comprising three sections of abutting crystalline substrates, the easy axis of each substrate being orthogonal to that of its neighbors. Each substrate is formed with a pair of waveguide sections which couple with those of the other sections, when the substrates are abutted, to form a pair of waveguide channels across the substrate sections. Sets of electrodes for directing horizontal and vertical electric fields through one waveguide channel are also formed on the substrate sections symmetrically about an axis of symmetry.

Abstract: An optical waveguide coupler having intersecting deep and shallow grooves in a planar solid substrate, in which the deep groove accommodates an alignment fiber for fine vertical alignment of an optical fiber with another optical fiber or with an optical component such as a switch, modulator, multiplexer or source of light. The shallow groove accommodates the optical fiber. The alignment fiber may be tapered or have any configuration such that its manipulation causes the alignment fiber to contact the underside of the optical fiber for raising or lowering the optical fiber. There may be a plurality of shallow and deep grooves for coupling more than one optical fiber.

Abstract: A recreational game toy for launching and catching projectiles or missiles comprising a target for projectiles or missiles and an acceleration element such as elastic band, spring, and bow-and-arrow wherein said target is incorporated with an attachment element, such as self-fastening textile materials (Velcro; Trade Name), to releasably hold projectiles or missiles to said target, and said target is connected to or engaged with said acceleration element.

Abstract: Optical devices and waveguides using a thin film optical waveguide having a two dimensional array of perturbations associated therewith or with adjacent optically coupled layers. The array is regular and forms periodic variations in two non-coincident directions which serve to reflect or scatter light waves into controllable transverse modes of propagation. Lasers as well as passive devices are disclosed.