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Electro-optic (EO) modulation devices, which utilize an external electric field to modulate a beam of optical radiation, are strongly affected by parasitic effects, which change the polarization state of the optical beam. As a result, very small changes in the birefringence or optical path length within the EO material can result in very large fluctuations of the amplitude and phase of the optical modulation signal. A method of actively analyzing the modulated beam is described and demonstrated, which eliminates these fluctuations and keeps the modulation device stably operating at its peak responsivity. Applications to electric field detection and measurements are discussed. OCIS codes: 230.2090, 190.4400, 230.4110.

We report structural, compositional, and magnetic properties for a commercially available doped barium hexaferrite material produced by Temex Ceramics. The material is designed to absorb electromagnetic radiation near the upper edge of the Ku frequency band (~18 GHz) and may serve as an important component to microwave circuitry. To aid in the development of such circuits that may utilize this or similar materials, we present results of the material properties of the raw starting powder, sintered pucks, and in the form of a film deposited by aerosol deposition. We find that the structural and magnetic properties are consistent with the parent compound, barium hexaferrite. Samples sintered at 1250 °C show some degree of preferred magnetic and structural orientation. Chemical analysis indicates that a titanium dopant has been added and that the material demonstrates broad absorption above 13 GHz that improves with sintering temperature. To our knowledge, this is the first report on the properties of this commercially available material. [ABSTRACT FROM AUTHOR]

The film structure and the directional microwave dielectric properties for highly strained SrTiO3 films deposited on (110) DyScO3 single-crystal substrate are characterized and studied for the in-plane film orientations [-110], [010], [110], and [100]. The observed in-plane anisotropic dielectric properties are explained based on the phenomenological thermodynamics of film strain.

Progress in high-performance computing demands significant advances in memory technology. Among novel memory technologies that promise efficient device operation on a sub-ns timescale, resistance switching between charge ordered phases of 1T-TaS2 has shown to be potentially useful for development of high-speed, energy efficient nonvolatile memory devices. Measurement of the electrical operation of such devices in the picosecond regime is technically challenging and hitherto still largely unexplored. Here, we use an optoelectronic "laboratory-on-a-chip" experiment for measurement of ultrafast memory switching, enabling accurate measurement of electrical switching parameters with 100 fs temporal resolution. Photoexcitation and electro-optic sampling on a (Cd,Mn)Te substrate are used to generate and, subsequently, measure electrical pulse propagation with intra-band excitation and sub-gap probing, respectively. We demonstrate high contrast nonvolatile resistance switching from high to low resistance states of a 1T-TaS2 device using single sub-2 ps electrical pulses. Using detailed modeling, we find that the switching energy density per unit area is exceptionally small, E A = 9.4 fJ/μm2. The speed and energy efficiency of an electronic "write" process place the 1T-TaS2 devices into a category of their own among new generation nonvolatile memory devices. [ABSTRACT FROM AUTHOR]

A general strategy for colloidal nanocrystal fabrication, which combines the concepts of precursor ligand stabilization and two-phase growth control, is presented. This dual approach was necessary in order to produce small HgS quantum dots emitting in the visible region of the spectrum.

Quanternary ammonium functionalized mesoporous thin films were prepared and was found to be on the order of 550-600 nm in the as-prepared condition, with shrinkage to 500-550 nm after extraction and 450 nm following calcinations. The d-spacing of the films was found to decrease linearly with increasing length of the ammonium chloride hydrocarbon segment.

Pulsed-layer deposition was used to deposit expitaxial Ba1-xSrxTiO3 solid-solution ferroelectric thin films onto (100)MgO and LaA103 substrates.

Research was conducted to examine imaging detectors based on the response of anisotropic layered materials. The inherent characteristics of naturally layered materials such as the high-temperature superconductors cause a transient voltage when a light pulse is absorbed. The amplitude is proportional to the absorbed energy. A phenomenological model of the effects consistent with observations on the first generation of sensors is presented.