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: Integrated optic tunable filters (IOTF) which for operation in many different wavelength ranges with different spectral properties. The IOTFs have one or more stages and/or channels formed in birefringent substrates and operate via polarization interferometric effects. Manufacture is via the use of variants of well-known processes used for making high speed integrated optic modulators. The IOTFs are for use in fiber-optic systems, although they can also be implemented in optic systems which are not fiber-optic. Other applications include wavelength division multiplexing, spectral analysis, and source output conditioning. Filtering may be active through the use of externally applied heat, stress, or electric fields.

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 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.