External Direct Current Voltage Research Articles

Voltage controllable Goos Hänchen and Imbert Fedorov shifts based on capacitor structure

The polarization properties and optical spot position of a 1550 nm linearly polarized laser beam reflected from ITO-Au(100 nm)/Ti(30 nm) interdigital electrodes-SiO2 glass (ITO-IE) or ITO-SiO2 microspheres-Au(100 nm)/Ti(30 nm) interdigital electrodes-SiO2 glass (ITO-SiO2-IE) are studied by a Thorlabs PAX 5710 IR3 polarimeter and a Thorlabs BP209-IR slit beam profiler detector under external direct current (DC) voltage. The Au is used as a reflective layer and the Ti is used as a buffer layer. The Au/Ti interdigital electrodes are prepared on SiO2 glass by thick film, printed circuit board and MEMS process. The surface morphology of the ITO-IE and ITO-SiO2-IE is obtained by a polarized light microscope. The polarization parameters' change of the linearly polarized laser beam reflected from ITO-IE is larger than that of the ITO-SiO2-IE. The maximum Goos Hänchen (GH) and Imbert Fedorov (IF) shifts of the linearly polarized laser beam reflected from the ITO-IE are 135.79 μm and −127.7 μm, while the GH and IF shifts of the linearly polarized laser beam reflected from ITO-SiO2-IE are 96.75 μm and −103.48 μm, when the external DC voltage increases from 0 to 3.0 V. The polarization properties and spatial position of the linearly polarized laser beam reflected from the ITO-IE and ITO-SiO2-IE capacitors show different trends. It is very important for the manufacture and design of optical displacement sensors.

Low error of garnet optical sensor induced by spin Hall effect

The Polarization properties of a linearly polarized laser beam reflected from garnet/Au, Ta/Nd2Fe14B/Ta/garnet/Au are studied by a Thorlabs PAX 5710 IR3 polarimeter undser external magnetic and direct current (DC) electric fields. The Nd2Fe14B, Ta and Au films are prepared by a DC magnetron sputtering method. The magnetic domains of the garnet films are obtained by a polarized light microscope. The magnetic domains in different garnet films show different distributions. The error of the Stokes parameter S1 is used to characterize the results. The S1 of the linearly polarized laser beam reflected from garnet/Au and Ta/Nd2Fe14B/Ta/garnet/Au shows different trends with the magnetic and electric fields. The maximum error S1 of garnet/Au is 0.005%, while the maximum error S1 of Ta/Nd2Fe14B/Ta/garnet/Au is 0.003%, when the external DC voltage increases from 0 to 2.5V, and the magnetic field increases from 0 to 100Oe. The low error may be induced by the spin Hall effect of garnet and Au. It is very important for the manufacture and design of optical current and voltage sensors.

Imbert–Fedorov Effects of Polarized Laser Beams Reflected from Dove Prism/Indium Tin Oxide Interface under Electric and Thermal Fields

Imbert–Fedorov (IF) effects of a polarized laser beam reflected from a dove prism/indium tin oxide (ITO) interface in the presence of electric and thermal fields are studied using a slit‐beam profiler and Stokes polarimeters. The IF effects of the polarized laser beams are primarily influenced by an electric field when the external direct current (DC) voltage is below 1.0 V, and it is mainly influenced by the thermal field when the external DC voltage changes from 1.0 to 4.0 V. The results exhibit a high resolution of 3 × 10−3 °C, due to the variation of the right‐ and left‐circular polarization properties of the reflected linearly polarized laser beams. In view of this influence of electric and thermal fields on IF effects, the results can be applied in polarization optics, temperature sensing, and light manipulation.

Electro-optic properties of ITO at a tilted quarter-wave-plate

The indium-tin-oxide (ITO) thin film is widely used in liquid crystal displays and silicon solar cells owing to its superior electrical and optical properties, which can be affected by external conditions. In this study, the optical properties of the ITO film were examined using stokes polarimeters and slit beam profiler under an external direct current voltage (EDCV) and a tilted quarter-wave plate (QWP). The results indicated that the Stokes parameters and degree of polarization of the laser beam that passes through the ITO film are mainly affected by the angle of the tilted QWP, which cannot be affected by the EDCV. Further, the transmittance of the ITO film decreased from 93.80% to 47.20%, as the EDCV increased from 0 V to 3.0 V, and the tilted QWP remained fixed at an angle. The Goos–Hänchen and Imbert–Fedorov shifts of the laser beam showed opposite trends when the EDCV increased from 0 V to 3.0 V and the angle of the tilted QWP changed from −5°to +5°.

Tunable Goos–Hänchen and Imbert–Fedorov shifts

Abstract The optical beam shift is a spatial displacement of an optical beam in geometrical optics that particularly occurs when a laser beam reflects from an interface. In this paper, the dependence of the Goos–Hanchen (GH) and Imbert–Fedorov (IF) shifts from the interface of quartz and garnet on the external direct current voltage (EDCV) are investigated by a Thorlabs BP209-IR slit beam profiler. The optical properties of the circularly polarized and linearly polarized laser beams are measured using a Thorlabs PAX 5710IR3 polarimeters. The results show that the change trend of the GH and IF shifts are the same, whereas the initial and terminal voltages are different. The maximum value of the GH and IF shifts are 20 . 9 μ m and 33 . 4 μ m when the EDCVs are at about 3.2 V and 2.0 V, respectively

Optical properties of monolayer polystyrene microspheres driven by a direct current

Polystyrene microspheres (PSMs) with diameters of 5 μm and 10 μm are prepared on garnet by a self-assembly method. The pressure generated by quartz sheet/PSM/garnet/graphite is measured by a resistance strain sensor as a function of the external direct current (DC) voltage. The surface morphology of the PSMs are observed by optical microscopy. The polarization properties of the linearly and circularly polarized laser beams with a wavelength of 1550 nm reflected from the different PSMs are researched by a Thorlabs PAX 5710 IR3 Polarization Analyzing System as a function of the external DC voltage. The results show that the PSMs with different sizes can be damaged when the external pressure exceeds its critical value of 3.0 MPa, but the critical DC voltages are different. The optical polarization properties of the circularly polarized laser beam can be changed with the external DC voltage, whereas the linearly polarized laser beam cannot be changed.

Optical beam shift induced by direct current

Optical beam shift is related to external conditions. Here, optical spot position and the polarization properties of the totally polarized, P‐polarized, and S‐polarized laser beams reflected from an aluminum film as a function of the external direct current (DC) voltage are measured by a Slit Beam Profiler and a polarimeter. The results show that the optical beam shift of the totally polarized laser beam and the S‐polarized laser beam jumps from 500 to 590 µm, and −10 to 70 µm, respectively, at different critical pressures, when the external DC value changes from 0 to 2.5 V, while the optical beam shift of the P‐polarized laser beam is small and has no jump. The degree of linear polarization of different polarized laser beams cannot change, while the degree of circular polarization of different polarized laser beams changes as a function of the external DC voltage value.

Oligonucleotide probes functionalization of nanogap electrodes.

Nanogap electrodes have attracted a lot of consideration as promising platform for molecular electronic and biomolecules detection. This is mainly for their higher aspect ratio, and because their electrical properties are easily accessed by current-voltage measurements. Nevertheless, application of standard current-voltages measurements used to characterize nanogap response, and/or to modify specific nanogap electrodes properties, represents an issue. Since the strength of electrical fields in nanoscaled devices can reach high values, even at low voltages. Here, we analyzed the effects induced by different methods of surface modification of nanogap electrodes, in test-voltage application, employed for the electrical detection of a desoxyribonucleic acid (DNA) target. Nanogap electrodes were functionalized with two antisymmetric oligo-probes designed to have 20 terminal bases complementary to the edges of the target, which after hybridization bridges the nanogap, closing the electrical circuit. Two methods of functionalization were studied for this purpose; a random self-assembling of a mixture of the two oligo-probes (OPs) used in the platform, and a selective method that controls the position of each OP at selected side of nanogap electrodes. We used for this aim, the electrophoretic effect induced on negatively charged probes by the application of an external direct current voltage. The results obtained with both functionalization methods where characterized and compared in terms of electrode surface covering, calculated by using voltammetry analysis. Moreover, we contrasted the electrical detection of a DNA target in the nanogap platform either in site-selective and in randomly assembled nanogap. According to our results, a denser, although not selective surface functionalization, is advantageous for such kind of applications.

A beam splitter driven by the garnet-graphite interface effect

Garnet film is widely used as a key element of optical sensors due to its Faraday effect. The polarization plane of the transmitted, linearly polarized light can be rotated when the garnet interacts with an external magnetic field. Here, an optical spot and the polarization state of a laser beam reflected from a garnet-graphite interface as a function of the external direct current (DC) voltage are measured by a Slit Beam Profiler and a Polarization Analyzing System. The results show that the garnet-graphite stress can be generated as a function of an external DC voltage, that the linearly polarized laser beam can be split into two optical spots, and that the maximum distance is 0.68 mm, while the polarization properties of the laser beam remained unchanged.

A tunable acoustic metamaterial with double-negativity driven by electromagnets.

With the advance of the research on acoustic metamaterials, the limits of passive metamaterials have been observed, which prompts the studies concerning actively tunable metamaterials with adjustable characteristic frequency bands. In this work, we present a tunable acoustic metamaterial with double-negativity composed of periodical membranes and side holes, in which the double-negativity pass band can be controlled by an external direct-current voltage. The tension and stiffness of the periodically arranged membranes are actively controlled by electromagnets producing additional stresses, and thus, the transmission and phase velocity of the metamaterial can be adjusted by the driving voltage of the electromagnets. It is demonstrated that a tiny direct-current voltage of 6V can arise a shift of double-negativity pass band by 40% bandwidth, which exhibits that it is an easily controlled and highly tunable acoustic metamaterial, and furthermore, the metamaterial marginally causes electromagnetic interference to the surroundings.

A polymer/clay nanocomposite gel via chlorinated paraffin solvent initiated photopolymerization with electrorheological performance

This communication reports a mild preparation of a polymer/clay nanocomposite gel of chlorinated paraffin with an electrorheological response to an external direct-current voltage due to the alignment of the clay within the gel networks.

Effects of applied electrical field on electronic structures in LaNiO3 conductive metallic oxide film: An optical spectroscopic study

The reflectance spectra of LaNiO3 film on silicon have been investigated in the wavelength range of 190–2650 nm (0.47–6.5 eV) under different external direct-current voltage. The Drude–Lorentz dispersion model is used to extract the optical function. The O 2p to Ni 3d electronic transition can be uniquely assigned to the energy of about 1.96 eV and decreases with decreasing applied voltage. The discrepancy from the real part of dielectric function with the applied voltage has a strong spectral dependence. The optical conductivity variation under different external voltage indicates that the electrical field can induce the modification of the carrier transport.