Papers by Keyword: Electro-Optic

Abstract: The application of an external electric field to the surface plasmon resonance (SPR) system of green-synthesized magnetite (Fe₃O₄) nanoparticles (MNPs) is very promising for increasing the SPR detection signal. Electro-optic surface plasmon resonance (EOSPR) behavior of MNPs has been successfully carried out. The EOSPR system was investigated using the Kretschmann configuration with the prism/Au thin film/MNPs/air layer arrangement and applying an electric voltage of 0 V, 2 V, 4 V, and 6 V. In this study, we synthesized MNPs using the green synthesis approach from moringa oleifera extract. The benefits of green synthesis include being safe, affordable, clean, and ecologically friendly processes. X-ray diffraction results obtained crystal size of the MNPs is about 9.2 nm with inverse spinel face-centered cubic crystal structure. Fourier transforms infrared characterization showed the presence of Fe-O bonds at wave numbers 569 cm^-1 and 629 cm^-1, indicating that MNPs were successfully formed. The saturation magnetization of the samples is 55.3 emu/g. The SPR angle of the SPR system Prism/Au thin film/air without the addition of MNPs is 44.66°. After being deposited by MNPs and induced by a voltage of 0 V, 2 V, 4 V, and 6 V, the SPR angles changed to 44.87°, 44.90°, 44.95° and 45.12°. The addition of MNPs and an external electric field causes the SPR angle to increase. The results of this study can provide new insights into the development of optical devices that can be manipulated electrically and have the potential for future biosensor applications.

Abstract: (100)-oriented PLZT ((Pb_1-x, La_x) (Zr_y,Ti_1-y)_1-x/4O₃, x/y=9/65) films of up to ~ 1.23 μm have been developed on LaAlO₃ single crystal substrate by magnetron sputtering. The as-grown PLZT thin films exhibit high optical transparency in visible and near-infrared light wavelength and high quadratic (Kerr) EO coefficients. Prism coupler measurements reveal that the PLZT thin films possess large refractive index, as high as 2.524 in TE model and 2.481 in TM model. The transparency of >70% in the range of λ= 500-1200 nm, the optic band gap of 3.42 eV and the quadratic electro-optic (EO) coefficient of 3.38 x 10^-17 (m/V)² have been measured in the films. Due to the large EO coefficient and the micrometric thickness, the as-developed PLZT films have great potential in developing longitudinal-or transverse-type EO devices in electric and optic field

Abstract: We report a high electo-optic coefficient (r₃₃) of 175 pm/V in guest-host polymer films made by mixing amorphous polycarbonate with the chromophore, PYR-3 that was synthesized by our team. We have previously shown that PYR-3 has a large 2^nd order nonlinear optical figure of merit. The measured r₃₃ is five times larger than that of conventional inorganic materials such as lithium niobate. The decay of r₃₃ with time has been studied for more than 1000 hours at room temperature and ambient atmosphere, and we find that the r₃₃ value gradually reduced to a stable value of 34 pm/V after 40 days.

Abstract: Disruptive inventions in electroceramics arose out of need for greatly improved properties or short-supply of existing materials, or, more importantly, serenpedity. In the case of ceramic capacitors, the key property of the material, dielectric constant, jumped from less than 10 (mica) to 100 (titania) to over 1000 (barium titanate ceramics) to over 10,000 (relaxor ferroelectrics) to over 100,000 (multilayer ceramics). The challenge for miniaturization demanded by integrated circuits was thus met. An excellent insulator such as barium titanate was converted into a good conductor by doping but the unexpected discovery was the abrupt increase in electrical resistivity over a million fold at the Curie temperature, opening new vistas of applications. The disruptive invention of superconductivity in oxide ceramics, that too at easily accessible, above liquid nitrogen, temperatures created unprecedented scientific efforts. The discovery of piezoelectric properties in lead zirconate titanate ceramics totally transformed the entire field of transducers, sensors and actuators. Mixing a piezoelectric ceramic powder and a polymer into a composite with controlled connectivity in 0, 1, 2 or 3 directions led to an unbelievable range of piezoelectric and electrostrictive properties and applications. Ceramics, noted for their opacity, have become endowed with superior electro-optic properties by magical alchemy.