Abstract: An optical switch, particularly useful as a bistable cross-connect matrix. Parallel input waveguides and parallel output waveguides are formed on a substrate at perpendicular angles so as to intersect. A 45.degree. slot is formed across each intersection and is filled with a fluid having a refractive index matching the waveguide material. Electrodes are positioned adjacent the slots and are selectively activated to electrolytically convert the fluid to gaseous bubbles, thereby destroying the index matching across the slot and causing light to be reflected by the slot rather than propagating across the slot. In the presence of a catalyst, a pulse of opposite polarity or of sufficient size and of the same polarity will destroy the bubble.

Abstract: A method of producing a sloped surface in a semiconductor material. In the area where the slope is desired a dynamic mask is applied to the surface of the semiconductor. A standard mask is applied over the dynamic mask and patterned so that its edge laterally defines the bottom of the desired slope. The sample is then immersed in an etchant that etches the dynamic mask faster than the semiconductor material. The standard mask is not appreciably etched. The dynamic mask is progressively etched laterally, thereby dynamically exposing more of the semiconductor material to etchant and producing a sloped surface therein.

Abstract: Several types of nonlinear characteristics are provided in an optical device wherein at least two optical materials are constructed to provide a waveguide structure. At least one of the materials has a dominant nonlinear characteristic over the length of the waveguide that is commonly referred to as the Kerr effect. The index of refraction in this material is a function of the light intensity in the waveguide. By selecting materials that provide either positive or negative Kerr coefficients, and by constructing the device with the nonlinear material either as the core or as the cladding layer, power output versus input characteristics that exhibit both limiting and amplification can be provided. A bistable characteristic is provided in one of the embodiments by terminating the waveguide structure with a mirror. Specific embodiments using carbon disulfide and polydiacetylene as the nonlinear materials are disclosed.

Abstract: The present invention relates to a high speed optical switch and the use of such switches to form a time division demultiplexer. The optical switch comprises a length of linear material (12) including an outer surface on a portion of which is formed a layer of nonlinear material (11) to form a nonlinear interface (10) at the boundary of the two materials. An input data light beam (14) is propagated in the linear material with a predetermined intensity and angle of incidence on the nonlinear interface to, by itself, cause total reflection of the input beam. A control light beam (11) is also selectively energized and directed at the nonlinear interface with an intensity and angle of incidence to cause a portion of the input data beam to be formed into a self-focused channel or beam propagating in the nonlinear material. The self-focused beam can then be detected at an edge of the nonlinear material.

Abstract: The invention provides apparatus comprising at least two beams of coherent radiation directed so as to intersect and form a standing wave pattern having a period .LAMBDA. in an optically responsive medium. The optically responsive medium is a colloidal suspension of dielectric particles in a liquid medium, the dielectric particles and liquid having different indices of refraction, and the diameter of the particles being less than or approximately equal to the period .LAMBDA.. The dielectric particles are arranged into a grating by the electric fields carried by the beams of coherent radiation. In an embodiment of the invention, the dielectric particles are small dielectric spheres. The dielectric particles and the liquid may have approximately equal mass densities. A third beam of light may generate an output beam of light by degenerate four-wave mixing processes incorporating a dielectric grating made by the electric fields carried by the beams of coherent radiation.

Abstract: Many prior art bistable optical devices require resonant optical cavities and are therefore limited in their operation due to the long lifetimes associated with their high-finesse cavities. A bistable optical device that does not use a resonant cavity is disclosed wherein a nonlinear medium whose index of refraction increases with increased light intensity is arranged to have input and output faces into which and out of which a laser beam having a nonuniform spatial profile can be propagated. A mirror having a predetermined area of reflectivity is positioned with respect to the output face of a nonlinear medium so as to reflect only the light energy that propagates in an area at the output face that is approximately equal to the area which the beam presents at this face when the beam is propagating at a critical power level, that is, when the beam is self-trapped.

Abstract: A time-division multiplexed spectrometer (TMS) which can convert the output from a pulsed continuum radiation source into a time- and wavelength-division multiplexed pulse train is provided, by a single spectrometer (1, 2) when: (a) an input source (100) is terminated at the image plane of the spectrometer at a first position which is displaced from the symmetry plane, (b) the first end of a set of optical fibers (100-110), each having a different length, are determined at the image plane at positions which are displaced in the opposite direction from the symmetry plane as is the first position, whereby narrowband portions of the output spectrum are picked up and delayed by different amounts, (c) the second end of the set are terminated at the image plane at positions which are reflections of the terminations of the first end about the symmetry plane, whereby the signals are reinjected into the instrument and refocused onto a second position at the image plane corresponding to the reflection of the first posi

Abstract: A multiposition optical switch is disclosed in which two quarter-period graded refractive index (GRIN) lenses (1 and 2) having first (1.2 and 2.1) and second (1.1 and 2.2) end surfaces are supported in a structure (33 and 34) in an axially aligned fashion with their first surfaces abutting in a substantially parallel relation which permits rotating at least one lens about the common lens axis (3 and 3.1). An input fiber (10) is affixed to the second surface (1.1) of one GRIN lens at a predetermined radial offset to the common lens axis; and a multiplicity of output fibers (11-16) are affixed to the second surface (2.2) of the other lens at the same predetermined radial offset, but at a plurality of angular displacements about the common lens axis. By rotating one lens relative to the other, light from the input fiber is selectively coupled to the output fibers.

Abstract: A rugged, compact optical switch is disclosed which comprises a quarter-period graded refractive index (GRIN) lens (1); a rotatable reflecting surface (2.1) disposed at a first surface (1.3) of the GRIN lens at an angle to the first surface; an optical source (8) mounted at the second surface (1.2) of the GRIN lens on the lens axis; and a plurality of optical receptors 6, 7, 9, 10, 11 and 12 mounted at the same second surface of the lens, all at the same distance from the lens axis but displaced at a plurality of angular positions about the lens axis. Rotation of the reflecting surface about the lens axis couples light between the optical source selectively to optical receptors at the appropriate angular orientation. The switch is reciprocal in that the common optical source may be an optical receptor and the various optical receptors, optical sources. Typically, the optical sources and receptors are optical fibers.

Abstract: A latent-imaging photopolymer system for recording thick refractive index patterns is disclosed. The system utilizes a porous matrix which has been sensitized by chemisorption of a photosensitive polymerization initiator. The sensitized matrix is exposed to light in the desired pattern. This light destroys initiator to impress the pattern. Then the pores are filled with a monomer composition. Finally the entire filled matrix is irradiated to induce polymerization initiation by the sensitizer remaining after the initial exposure. Polymerization produces locally induced refractive index gradients corresponding to the pattern of the light in the initial exposure step.

Abstract: A latent-imaging photopolymer system for recording thick refractive index patterns is disclosed. The system utilizes a porous matrix which has been sensitized by chemisorption of a photosensitive polymerization initiator. The sensitized matrix is exposed to light in the desired pattern. This light destroys initiator to impress the pattern. Then the pores are filled with a monomer composition. Finally the entire filled matrix is irradiated to induce polymerization initiation by the sensitizer remaining after the initial exposure. Polymerization produces locally induced refractive index gradients corresponding to the pattern of the light in the initial exposure step.

Abstract: A wavelength division optical multiplexer for combining single mode beams involves a lens formed in a thin-film waveguide and a reflection diffraction grating outside the waveguide.