Abstract: Dimpled plates for light distribution and concentration are provided. Also provided are apparatus incorporating the plates as waveguides, and methods for using the dimpled plates for distributing or concentrating input light. The dimpled plates are designed to spatially distribute light from each of one or more near point light sources into a pixelated light projection using an array of reflective conical light deflection elements.

Abstract: Dimpled plates for light distribution and concentration are provided. Also provided are apparatus incorporating the plates as waveguides, and methods for using the dimpled plates for distributing or concentrating input light. The dimpled plates are designed to spatially distribute light from each of one or more near point light sources into a pixelated light projection using an array of reflective conical light deflection elements.

Abstract: A fiber optic probe having one or more photodetectors bound thereto is provided. By directly integrating thin, flexible photodetectors with an optical fiber, the probes provide a compact structure that increases throughput and decreases cost, making it practical for a clinical use. In some embodiments, the fiber optic probes are small enough for insertion into the shaft of a needle, such as a biopsy needle.

Abstract: A fiber optic probe having one or more photodetectors bound thereto is provided. By directly integrating thin, flexible photodetectors with an optical fiber, the probes provide a compact structure that increases throughput and decreases cost, making it practical for a clinical use. In some embodiments, the fiber optic probes are small enough for insertion into the shaft of a needle, such as a biopsy needle.

Abstract: A radiation source or detector including a nested waveguide structure is provided. A smaller waveguide provides wave guiding for radiation of shorter wavelength. The smaller waveguide is embedded within a larger waveguide that provides wave guiding for radiation of longer wavelength. Wavelength conversion between the shorter wavelength and the longer wavelength can be realized through a nonlinear process.

Abstract: A THz radiation source comprising a dual waveguide heterostructure is provided. The dual waveguide heterostructure includes an optical waveguide contained within a larger THz waveguide layered structure. The radiation source provides a coherent guided wave of THz radiation which is generated via difference frequency mixing in a gain medium with a large second-order nonlinearity and propagated with low THz loss by a dielectric medium in the layered waveguide structure. The THz radiation source is compact, has a high power output, and may be operated in continuous-wave (CW) mode at room temperature.

Abstract: A radiation source or detector including a nested waveguide structure is provided. A smaller waveguide provides wave guiding for radiation of shorter wavelength. The smaller waveguide is embedded within a larger waveguide that provides wave guiding for radiation of longer wavelength. Wavelength conversion between the shorter wavelength and the longer wavelength can be realized through a nonlinear process.

Abstract: A THz radiation source comprising a dual waveguide heterostructure is provided. The dual waveguide heterostructure includes an optical waveguide contained within a larger THz waveguide layered structure. The radiation source provides a coherent guided wave of THz radiation which is generated via difference frequency mixing in a gain medium with a large second-order nonlinearity and propagated with low THz loss by a dielectric medium in the layered waveguide structure. The THz radiation source is compact, has a high power output, and may be operated in continuous-wave (CW) mode at room temperature.

Abstract: Machining of crystalline lithium niobate is carried out utilizing a laser having a beam with a wavelength near the absorption edge of lithium niobate. The laser beam is provided in pulses of short duration and at a repetition rate selected to ablate the surface of the lithium niobate without damaging the bulk material. Translation of the laser beam and the substrate with respect to each other can be carried out to define a trench of a desired geometry in the lithium niobate.

Abstract: Metal oxide films such as lithium niobate are formed in an amorphous state on a substrate such as lithium niobate and can be readily etched by conventional liquid or dry etchants. The amorphous film may then be converted by annealing to a crystalline form well suited to formation of electro-optical devices.

Abstract: Machining of crystalline lithium niobate is carried out utilizing a laser having a beam with a wavelength near the absorption edge of lithium niobate. The laser beam is provided in pulses of short duration and at a repetition rate selected to ablate the surface of the lithium niobate without damaging the bulk material. Translation of the laser beam and the substrate with respect to each other can be carried out to define a trench of a desired geometry in the lithium niobate.

Abstract: Electro-optic elements are formed in metal oxide films, such as lithium niobate, on a substrate such as lithium niobate for utilization in electro-optical devices. The electro-optic elements include trenches in the lithium niobate selected to improve the performance of the device. Traveling wave modulators may be formed with a waveguide having first and second arms, electrodes over the lithium niobate layer, and trenches formed in the layer to focus the electric field in the waveguide, resulting in improved modulator performance.

Abstract: Metal oxide films such as lithium niobate are formed in an amorphous state on a substrate such as lithium niobate and can be readily etched by conventional liquid or dry etchants. The amorphous film may then be converted by annealing to a crystalline form well suited to formation of electro-optical devices.

Abstract: A two-dimensional second order nonlinear lattice formed in a lattice body is utilized for performing a one-step optical carrier wavelength interchange between pairs of input optical signals. The lattice body includes sensitized regions arranged in a two-dimensional array in a matrix material with the sensitized regions differing from the matrix material in the sign of the second order susceptibility. When an optical pump signal is coupled to the lattice body at a frequency corresponding to the sum of the frequencies of the two input signals, nonlinear interactions in the lattice body produce wavelength interchange between the input signals, resulting in angularly deflected optical signals exiting the lattice body in which the signal information on the input signals is interchanged between the carrier frequencies of the two input signals.

Abstract: Er and Ti are co-diffused under controlled conditions into a single crystal of LiNbO.sub.3. The co-diffusion is used to produce a light amplifier in LiNbO.sub.3 that is suitable for use in integrated optic devices.

Abstract: An electrooptic directional coupler having first and second electrodes for influencing coupling between a segment of a first optical waveguide and a segment of a second optical waveguide, is operated by varying the potential of the first electrode relative to the second electrode during a first interval in accordance with a first function such that the first electrode remains at a first polarity relative to the second electrode, and varying the potential of the first electrode relative to the second electrode during a second interval in accordance with a second function such that the first electrode remains at a second polarity, opposite the first polarity, relative to the second electrode. The integral with respect to time over the first and second intervals of the potential of the first electrode relative to the second electrode is essentially zero.

Abstract: An electrooptical device comprises a substrate of electrooptic material having first, second and third optical waveguide formed therein. The first and second waveguides have first and second waveguide segments respectively, and the third waveguide has third and fourth waveguide segments extending adjacent the first and second waveguide segments respectively, so that first and second directional couplers are formed. The interaction length of the first directional coupler is slightly greater than an optimum interaction length for a predetermined wavelength and the interaction length of the second directional coupler is slightly less than an optimum interaction length for the predetermined wavelength. A first electrode structure influences the first directional coupler and a second electrode structure influences the second directional coupler.

Abstract: Apparatus for depolarizing light received from a source of light comprises a body of material that defines an optical waveguide, the material of the body and the length of the waveguide being such that when polarized light is propagated through the waveguide, light in one of two polarization eigen states is retarded relative to light in the other polarization eigen state by a time such as to destroy phase coherence between the polarization eigen states of the light emitted by the source. The relative amplitudes of the two polarization eigen states of polarized light entering the wave-guide are adjusted.