Abstract: An electro-optic electromagnetic field sensor system includes an electro-optic sensor located at an electromagnetic field sensing site for detecting an intensity of an electromagnetic field. The sensor changes an optical measuring signal received from a laser source to an optical sensor signal representative of the electromagnetic field intensity. An optical bias adjust unit optically coupled to the laser source adjusts the bias operating point of the electro-optic sensor responsive to an electrical bias adjust signal which includes a test signal component. A detector optically coupled to the electro-optic sensor converts the optical sensor signal to an electrical sensor signal and detects a feedback signal indicative of the transfer function of the electro-optic sensor operating on the test signal component. A bias control circuit electrically coupled to the optical bias adjust unit generates the bias adjust signal responsive to the feedback signal.

Abstract: An analog lightwave communication system comprises at least two optical transmitters for providing optical information signals at different optical wavelengths. A dense wavelength division multiplexer includes at least two inputs for receiving the optical information signals from the optical transmitters and multiplexes the optical information signals to a composite optical signal at an output. Each input of the dense wavelength division multiplexer comprises at least one optical resonant cavity comprising first and second reflecting materials spaced to permit resonance at a selected wavelength. A fiber optic transmission system coupled to the output of the dense wavelength division multiplexer receives the composite optical signal.

Abstract: A method for diffusing titanium into a single-crystal lithium niobate substrate and guided wave devices produced therefrom provide improved mode match with coupled fibers. Preferably, the titanium diffusion occurs at a diffusion temperature for a time between about 8 hours and about 18 hours. Outdiffusion of lithium oxide is allowed to occur during titanium diffusion. The outdiffused region, typically at least about 25 .mu.m, is much deeper than the titanium diffusion depth, typically about 5-10 .mu.m.

Abstract: A high fidelity, multi-output optical transmission system is configured utilizing a high power continuous wave YAG laser, multiport splitters, and linearized external modulation. An electro-optical modulator design in combination with a c.w. laser, power splits and couplers attains a multi-octave bandwidth transmitter possessing second and third order distortion characteristics of -60 db and a dynamic range >-140 db/Hz. The system includes multiple individually modulated transmitter outputs which effectively provides bandwidth multiplication with full redundancy for increased transmission reliability.

Abstract: A method for co-diffusing titanium and aluminum into a single-crystal lithium niobate substrate and guided wave devices produced therefrom are provided. Titanium diffused into the substrate forms a light guiding region. A layer of aluminum deposited over the light guiding region and diffused into the substrate buries the light guiding region below the substrate surface. In an alternate embodiment, a layer of aluminum forms a mode shaping region which surrounds the light guiding region on two sides. The mode shaping region has ordinary and extraordinary indices of refraction less than the substrate such that mode mismatch between a device fabricated thereby and an externally coupled fiber is reduced. The aluminum can be diffused into LiNbO.sub.3 at a much lower temperature without affecting diffused titanium guides. Preferably, the titanium diffusion occurs at about 1000.degree. to about 1100.degree. C. while further aluminum diffusion occurs at a lower temperature in the range of about 900.degree. to 950.

Abstract: A method for diffusing titanium into a single-crystal lithium niobate substrate and guided wave devices produced therefrom provide improved mode match with coupled fibers. Preferably, the titanium diffusion occurs at a diffusion temperature for a time between about 8 hours and about 18 hours. Outdiffusion of lithium oxide is allowed to occur during titanium diffusion. The outdiffused region, typically at least about 25 .mu.m, is much deeper than the titanium diffusion depth, typically about 5-10 .mu.m.

Abstract: A high fidelity, multi-output optical transmission system is configured utilizing a high power continuous wave YAG laser, multiport splitters, and linearized external modulation. An electro-optical modulator design in combination with a c.w. laser, power splits and couplers attains a multi-octave bandwidth transmitter possessing second and third order distortion characteristics of -60 dB and a dynamic range >-140 dB/Hz. The system includes multiple individually modulated transmitter outputs which effectively provides bandwidth multiplication with full redundancy for increased transmission reliability.

Abstract: An integrated optics print head includes an array of indepenedently driven semiconductor lasers disposed on a common substrate with their outputs coupled to an integrated waveguide structure. The integrated waveguide structure includes a multiplicity of "S" shaped, low-loss waveguides which have substantially the same length. Further, in order to reduce crosstalk, the region of the waveguide structure at the output where all the waveguides are in close proximity is made as short as possible while maintaining a parallel relation between the waveguide outputs.

Abstract: A process for forming a channel waveguide in which the channel geometry and the channel index of refraction vary oppositely along the channel length to keep the modal characteristic of the channel uniform uses non-uniform heating of a channel waveguide to cause non-uniform diffusion of the channel dopant. In one embodiment, the channel is passed under a laser at a non-uniform rate to expose the channel to different numbers of laser pulses.

Abstract: An optical modulator comprises a crystal whose top surface includes a channel waveguide whose axis makes an angle with the crystal optic axis larger than the critical angle for TE-polarized leaky mode propagation. An electrode structure overlies the top surface of the crystal for inducing mode conversion of TM-polarized waves propagating in the waveguide to lossy radiation modes.

Abstract: An M.times.N coupler uses a planar waveguide to couple each of M input channel waveguides to each of N output channel waveguides, the input guides and the output guides being disposed on opposite sides of the planar waveguide. Uniformity of coupling is improved by joining the input channel waveguides to the planar waveguide in a manner to focus the beams emitted by each input guide into the planar waveguide at a common focal point located near the center of the edge where the output guides join the planar waveguide.

Abstract: Integrated optic devices incorporating echelon gratings suitable for use in performing multi/demultiplexing functions in optical communications systems. The echelon gratings can be either reflection or transmissive types and are conveniently formed using conventional photolithographic techniques.

Abstract: Integrated optic resonant structures for use in optical communications and sensing applications requiring control or detection of electromagnetic radiation in the optical region of the spectrum. Preferably of planar form, the structures comprise a substrate made of a ferroelectric crystalline material in which there is formed by selectively exchanging protons for an ionic constituent of the substrate at least one optically continuous waveguiding region having predetermined resonant characteristics. At least one other waveguiding region is similarly formed in the substrate to optically couple with the resonant region and includes at least one port by which radiation can be coupled in and out of the substrate. The substrate material is preferably lithium niobate (LiNbO.sub.3) or lithium tantalate (LiTaO.sub.3) in which lithium ions are selectively exchanged for protons supplied by diffusion from a hydrogen rich acid.