The Experts below are selected from a list of 1527 Experts worldwide ranked by ideXlab platform
Chunxi Zhang - One of the best experts on this subject based on the ideXlab platform.
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optimization of detection accuracy of closed loop optical voltage sensors based on Pockels Effect
Sensors, 2017Co-Authors: Wei Deng, Chunxi Zhang, Pengjie WangAbstract:The influence of optical parameters on the performance of closed-loop optical voltage sensors (OVSs) based on Pockels Effect is analyzed and a control algorithm is proposed to suppress the nonlinearity caused by the unideal parameters of optical devices for optimizing the detection precision of OVSs. First, a quantified model of the feedback phase demonstrates how the optical parameters of optical devices (including light source, polarizer, 45° fusion point, Faraday rotator and half-wave plate) result in the nonlinearity of closed-loop OVSs. Then, the parameter indexes of different optical devices are put forward to instruct the manufacturing process of the optical system. Furthermore, a closed-loop control algorithm is investigated to improve the measurement accuracy of nonlinear OVSs considering the unideal parameters. The experiment results indicate that additional bias caused by undesirable optical parameters is obviously decreased so that the measurement accuracy of OVSs satisfies the demand of IEC60044-3 for 0.1 level measurement accuracy, which verifies the Effectiveness and correctness of the methods for suppressing the impact of unideal optical parameters on OVSs.
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Analysis and Design of Loop Gains to Optimize the Dynamic Performance of Optical Voltage Sensor Based on Pockels Effect
Journal of Lightwave Technology, 2015Co-Authors: Liyang Cui, Zhili Lin, Xiaxiao Wang, Chunxi ZhangAbstract:A design method of loop gains is proposed for improving the fast dynamic tracking performance of optical voltage sensor (OVS) based on Pockels Effect. The distribution principle of loop gains is investigated in theory according to the characteristics of closed-loop error of OVS. Based on the obtained distribution principle of loop gains, the hardware circuit and the control parameters of the controller are designed to improve the signal to noise ratio (SNR) of closed-loop error and the dynamic performance of OVS, respectively. The experimental results demonstrate that the system can achieve the high dynamic performance under the high detection precision: OVS can accurately track 13th harmonic with 1.57% measurement error and 4.24° phase error, and the long term steady accuracy of power frequency voltage is within ±0.1%. The experimental results validate the Effectiveness of our new design method of loop gains.
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an analysis on the optimization of closed loop detection method for optical voltage sensor based on Pockels Effect
Journal of Lightwave Technology, 2014Co-Authors: Liyang Cui, Zhili Lin, Chunxi ZhangAbstract:In engineering practice, the closed-loop optical voltage sensor (OVS) based on Pockels Effect cannot reach the required precision level mainly due to the various disturbance and noise of system, so the application of OVS for low voltage measurement is restricted. Considering the cross coupling of the main and second closed-loops, the model of disturbance and noise of system that adopts the four-state modulation method is analyzed in the main closed-loop of OVS. Based on the established noise-perturbed stochastic model of OVS, we design a closed-loop detection algorithm for the OVS system to guarantee the mean-square exponential stability with a prescribed H∞ performance in order to optimize the detection precision of OVS. The experimental results show that the detection precision of OVS is 0.144 V while the relative measurement error of the scale factor is within ± 0.15% in measuring low AC voltages from 140 to 500 V, which verifies the Effectiveness of the proposed detection scheme.
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signal detection for optical ac and dc voltage sensors based on Pockels Effect
IEEE Sensors Journal, 2013Co-Authors: Liyang Cui, Rui Wang, Zhili Lin, Chunxi ZhangAbstract:A new signal detection technology is presented to improve the stability and robustness of the optical voltage sensors (OVSs) based on Pockels Effect for the measurement of ac and dc voltages. The closed-loop error of the OVS is a weak and nonlinear signal vulnerable to unavoidable noise. Simultaneously, the nonlinearity and noise in physical components of OVSs are the major causes of performance deterioration of system in practical high-voltage applications. We design a signal detection hardware that can precisely extract nonlinear closed-loop error and be applicable for the measurement of ac and dc voltages. Based on the signal detection hardware, we analyze the dynamic model of closed-loop OVSs considering the Effects of nonlinearity, noise, and time-delay. The control scheme of OVS is proved to obtain exponential stability with a desired attenuation level of noise. The experimental results show that the OVS has a wide bandwidth up to 24.5 kHz, the maximum step voltage 19.5 kV, the accuracy of ac and dc voltage within 0.2% and 0.5%, respectively. The experimental results validate the Effectiveness and usefulness of our proposed detection method.
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Design of Closed-Loop Detection System for Optical Voltage Sensors Based on Pockels Effect
Journal of Lightwave Technology, 2013Co-Authors: Hui Li, Lan Bi, Rui Wang, Lijing Li, Chunxi ZhangAbstract:A closed-loop detection system is established to make optical voltage sensors (OVSs) based on Pockels Effect particularly ideal for high-voltage applications. For the closed-loop OVSs, the signal intensity fluctuation due to temperature variation contributes to the gain drift of the forward channel and finally influences the dynamic performance of the OVSs. Meanwhile, the closed-loop error of the OVS is also a weak signal that is hard to be accurately extracted. In this work, we propose a signal detection circuit based on weak signal detection theory to reduce noise levels for improving detection accuracy of OVS. In consideration of the influence of signal intensity fluctuation, we design a control algorithm for the closed-loop detection system to guarantee that the OVS is exponentially stable in order to have a fast dynamic response. The experimental results show that the OVS based on the proposed closed-loop system has accuracy within 0.2%, a fast rise time less than 25.2 μs and a wide bandwidth up to 24.5 kHz.
Eiji Tokunaga - One of the best experts on this subject based on the ideXlab platform.
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giant Pockels Effect in an electrode water interface for a liquid light modulator
OSA Continuum, 2019Co-Authors: Daisuke Hayama, Shunpei Yukita, Takayoshi Kobayashi, Keisuke Seto, Kyohei Yamashita, Eiji TokunagaAbstract:We report the development of a light modulator using the Pockels Effect of water in a nanometer-thick electric double layer on an electrode surface. The modulator comprises a transparent-oxide electrode on a glass substrate immersed in an aqueous electrolyte solution. When an optical beam is incident such that it is totally reflected at the electrode-water interface, the light is modulated at a specific wavelength with a near-100% modulation depth synchronized with the frequency of the applied AC voltage. This result was reproduced by a calculation that assumes a change in the refractive index of −0.1 in a 2-nm electric double layer and of −0.0031 in a 30-nm space-charge layer formed at the interface between the electrolyte aqueous solution and the transparent electrode. This is the first report of an optical modulator that uses the interfacial Pockels Effect of a material that does not allow for the Pockels Effect in the bulk. The principle of giant optical modulation is explained by invoking the large Pockels coefficient of interfacial water and a Fabry–Perot-resonance Effect in the transparent thin-film electrode.
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Mechanisms of the anomalous Pockels Effect in bulk water
Optical Review, 2018Co-Authors: Shunpei Yukita, Yuto Suzuki, Naoyuki Shiokawa, Takayoshi Kobayashi, Eiji TokunagaAbstract:The “anomalous” Pockels Effect is a phenomenon that a light beam passing between two electrodes in an aqueous electrolyte solution is deflected by an AC voltage applied between the electrodes: the deflection angle is proportional to the voltage such that the incident beam alternately changes its direction. This phenomenon, the Pockels Effect in bulk water, apparently contradicts what is believed in nonlinear optics, i.e., macroscopic inversion symmetry should be broken for the second-order nonlinear optical Effect to occur such as the first-order electro-optic Effect, i.e., the Pockels Effect. To clarify the underlying mechanism, the dependence of the Effect on the electrode material is investigated to find that the Pockels coefficient with Pt electrodes is two orders of magnitude smaller than with indium tin oxide (ITO) electrodes. It is experimentally confirmed that the Pockels Effect of interfacial water in the electric double layer (EDL) on these electrodes shows an electrode dependence similar to the Effect in bulk water while the Effects depend on the frequency of the AC voltage such that the interfacial signal decreases with frequency but the bulk signal increases with frequency up to 221 Hz. These experimental results lead to a conclusion that the beam deflection is caused by the refractive index gradient in the bulk water region, which is formed transiently by the Pockels Effect of interfacial water in the EDL when an AC electric field is applied. The refractive index gradient is caused by the diffuse layer spreading into the bulk region to work as a breaking factor of inversion symmetry of bulk water due to its charge-biased ionic distribution. This mechanism does not contradict the principle of nonlinear optics.
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Giant Pockels Effect of polar organic solvents and water in the electric double layer on a transparent electrode
RSC Adv., 2017Co-Authors: Hironori Kanemaru, Shunpei Yukita, Takayoshi Kobayashi, Hajime Namiki, Yugo Nosaka, Eiji TokunagaAbstract:The Pockels Effect of polar organic solvents and water within the electric double layer (EDL) on an indium–tin–oxide (ITO) electrode is studied to find that water has the largest Pockels coefficient (230 pm V−1), followed in order by methanol (200 pm V−1), ethanol (84 pm V−1), and dimethyl sulfoxide (DMSO) (20 pm V−1). Electrolyte solutions of water and methanol have nearly the same magnitude of Pockels coefficient, while ethanol and DMSO solutions exhibit two and ten times smaller Pockels coefficients than the methanol solution, respectively. The Pockels coefficient scales well with the hydrogen-bond strength (or average cluster size) divided by the solvent viscosity. This suggests that hydrogen bonding and viscosity play crucial roles in the mechanism of the Pockels Effect of these liquids.
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anomalously large electro optic Pockels Effect at the air water interface with an electric field applied parallel to the interface
Applied Physics Letters, 2016Co-Authors: Yuto Suzuki, Shunpei Yukita, Takayoshi Kobayashi, Kengo Osawa, Eiji TokunagaAbstract:The optical Pockels Effect was observed at the air-water interface by electromodulation spectroscopy. When an AC electric field of frequency f was applied parallel to a water surface between Pt electrodes, the field induced a change in the transmitted light intensity synchronized at 1f proportional to the field strength. The 1f signals dominated over 2f signals by one order of magnitude and the signal disappeared when the electrodes were completely immersed under the water surface, strongly suggesting that the observed phenomena were due to the Pockels Effect at the air-water interface. The Pockels coefficient was estimated to be |r|= 1.4 × 105 pm/V, which is much larger than that at the solid-water interface. However, this is unusual because the parallel electric field does not induce the break in inversion symmetry required for the appearance of the Pockels Effect. The electrowetting Effect was experimentally ruled out as a mechanism for the Pockels Effect, and this made the existence of a field perpend...
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deflection switching of a laser beam by the Pockels Effect of water
Applied Physics Letters, 2012Co-Authors: Shunpei Yukita, Naoyuki Shiokawa, Takayoshi Kobayashi, Hajime Namiki, Hiroki Kanemaru, Eiji TokunagaAbstract:Deflection of a laser beam in response to an electric field was detected with a Sagnac interferometer. A laser beam was aligned to travel between two electrodes immersed in aqueous electrolyte solution. When the alternating electric field was applied perpendicular to the beam axis, the direction of the beam deflection was switched synchronously with the field alternation as expected for the Pockels Effect. Broken inversion symmetry is prerequisite to the linear electrooptic Effect, but surprisingly the Effect was observed even when the laser beam travels through the bulk water a few millimeters away from the electrode surface.
Laurent Vivien - One of the best experts on this subject based on the ideXlab platform.
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high speed characteristics of strain induced Pockels Effect in silicon conference presentation
Silicon Photonics: From Fundamental Research to Manufacturing, 2018Co-Authors: Mathias Berciano, Pedro Damas, Guillaume Marcaud, Daniel Benedikovic, Eric Cassan, Xavier Le Roux, Carlos Alonsoramos, Delphine Marrismorini, P Crozat, Laurent VivienAbstract:With the fast growing demand of data, current chip-scale communication systems based on electrical links suffer rate limitations and high power consumptions to address these new requirements. In this context, Silicon Photonics has proven to be a viable alternative by replacing electronic links with optical ones while taking advantage of the well-established CMOS foundries techniques to reduce fabrication costs. However, silicon, in spite of being an excellent material to guide light, its centrosymmetry prevents second order nonlinear Effects to exist, such as Pockels Effect an electro-optic Effect extensively used in high speed and low power consumption data transmission. Nevertheless, straining silicon by means of stressed thin films allows breaking the crystal symmetry and eventually enhancing Pockels Effect. However the semiconductor nature of silicon makes the analysis of Pockels Effect a challenging task because free carriers have a direct impact, through plasma dispersion Effect, on its efficiency, which in turn complicates the estimation of the second order susceptibility necessary for further optimizations. However, this analysis is more relaxed working in high-speed regime because of the frequency limitation of free carriers-based modulation. In this work, we report experimental results on the modulation characteristics based on Mach-Zehnder interferometers strained by silicon nitride. We demonstrated high speed Pockels-based optical modulation up to 25 GHz in the C-band.
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Strained silicon photonics for Pockels Effect based modulation
2017Co-Authors: Mathias Berciano, Pedro Damas, Guillaume Marcaud, Xavier Le Roux, Paul Crozat, Carlos Alonso Ramos, Daniel Benedikovic, Delphine Marris-morini, Eric Cassan, Laurent VivienAbstract:We present on experimental results of straininduced Pockels Effect in silicon based on Mach-Zehnder interferometer modulators. We theoretically studied both Pockels Effect and carrier parasitic Effect in silicon under an electric field. We demonstrated high speed Pockels-based optical modulation up to 25 GHz.
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Pockels Effect in strained silicon photonics conference presentation
Proceedings of SPIE, 2017Co-Authors: Laurent Vivien, Mathias Berciano, Pedro Damas, Guillaume Marcaud, Daniel Benedikovic, Xavier Le Roux, Carlos Alonsoramos, Delphine Marrismorini, P Crozat, Eric CassanAbstract:Silicon photonics has generated a strong interest in recent years, mainly for optical communications and optical interconnects in CMOS circuits. The main motivations for silicon photonics are the reduction of photonic system costs and the increase of the number of functionalities on the same integrated chip by combining photonics and electronics, along with a strong reduction of power consumption. However, one of the constraints of silicon as an active photonic material is its vanishing second order optical susceptibility, the so called χ(2) , due to the centrosymmety of the silicon crystal. To overcome this limitation, strain has been used as a way to deform the crystal and destroy the centrosymmetry which inhibits χ(2). The paper presents the recent advances in the development of second-order nonlinearities including discussions from fundamental origin of Pockels Effect in silicon until its implementation in a real device. Carrier Effects induced by an electric field leading to an electro-optics behavior will also be discussed.
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strain induced Pockels Effect in silicon waveguides conference presentation
Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, 2017Co-Authors: Mathias Berciano, Pedro Damas, Guillaume Marcaud, Daniel Benedikovic, Eric Cassan, Xavier Le Roux, Carlos Alonsoramos, Delphine Marrismorini, P Crozat, Laurent VivienAbstract:With the increasing demand of data, current chip-scale communication systems based on metallic interconnects suffer rate limitations and power consumptions. In this context, Silicon photonics has emerged as an alternative by replacing the classical copper interconnects with silicon waveguides while taking advantage of the well-established CMOS foundries techniques to reduce fabrication costs. Silicon is now considered as an excellent candidate for the development of integrated optical functionalities including waveguiding structures, modulators, switches… One of the main challenges of silicon photonics is to reduce the power consumption and the swing voltage of optical silicon modulators while increasing the data rate speed. However, silicon is a centrosymmetric crystal, vanishing the second order nonlinear Effect i.e. Pockels Effect which is intrinsically a high speed Effect. To overcome this limitation, mechanical stresses on silicon to break the crystal symmetry can be used depositing a strained overlayer. In this work, we have studied the Effect of the stress layer in the modulation characteristics based on Mach-Zehnder interferometers. The deposition of silicon nitride as the stress layer and its optimization to induce the maximum Effect will be presented.
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Pockels Effect in Strained Silicon Waveguides
2017Co-Authors: Mathias Berciano, Pedro Damas, Guillaume Marcaud, Xavier Le Roux, Paul Crozat, Daniel Benedikovic, Delphine Marris-morini, Eric Cassan, Carlos Alonso Ramos, Laurent VivienAbstract:With the increasing demand of data current chip-scale communication systems based on metallic interconnects suffer from rate limitations and power consumptions. In this context, Silicon Photonics has emerged as an alternative solution replacing the classical copper interconnects by silicon waveguides while taking advantage of the well-established CMOS foundries techniques to reduce fabrication costs. Silicon is now considered as an excellent candidate for the development of integrated optical functionalities. Among all photonic devices required for an optical link, optical modulator is one of the main building blocks. One of the main challenges of Silicon Photonics is the reduction of both power consumption and swing voltage of optical silicon modulators while increasing the data transfer rate speed. However silicon is a centrosymmetric crystal, vanishing the second order nonlinear Effect i.e. Pockels Effect which is intrinsically high speed. Nevertheless it has been showed [1] that mechanical stresses, provided by depositing a strained overlayer, can break the crystal symmetry and eventually unlock Pockels Effect in silicon. Since then several studies have been performed [2-4] in order to improve the later. But a recent investigation [5] demonstrated that carrier Effects have a drastic influence on the measured electro-optic Effect. Indeed both plasma dispersion Effect and Pockels Effect act together under an electric field in strained silicon which have led to an overestimation of the second order nonlinear susceptibility. One way to separate these Effects consists in the increasing of the modulation speed [6] in order to minimize the impact of free carriers. In this work, we have studied the Effect of the stress layer in the modulation characteristics based on Mach-Zehnder interferometers (Fig. 1) in the microwave range. DC and high speed characteristics (Fig. 2) will be presented and discussed.
Ingo Breunig - One of the best experts on this subject based on the ideXlab platform.
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Pockels Effect based adiabatic frequency conversion in ultrahigh q microresonators
Optics Express, 2020Co-Authors: Yannick Minet, Luis Reis, Jan Szabados, Christoph S Werner, Hans Zappe, K Buse, Ingo BreunigAbstract:Adiabatic frequency conversion has some key advantages over nonlinear frequency conversion. No threshold and no phase-matching conditions need to be fulfilled. Moreover, it exhibits a conversion efficiency of 100 % down to the single-photon level. Adiabatic frequency conversion schemes in microresonators demonstrated so far suffer either from low quality factors of the employed resonators resulting in short photon lifetimes or small frequency shifts. Here, we present an adiabatic frequency conversion (AFC) scheme by employing the Pockels Effect. We use a non-centrosymmetric ultrahigh-Q microresonator made out of lithium niobate. Frequency shifts of more than 5 GHz are achieved by applying just 20 V to a 70-µm-thick resonator. Furthermore, we demonstrate that with the same setup positive and negative frequency chirps can be generated. With this method, by controlling the voltage applied to the crystal, almost arbitrary frequency shifts can be realized. The general advances in on-chip fabrication of lithium-niobate-based devices make it feasible to transfer the current apparatus onto a chip suitable for mass production.
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Pockels Effect based adiabatic frequency conversion in ultrahigh q microresonators
arXiv: Optics, 2019Co-Authors: Yannick Minet, Luis Reis, Jan Szabados, Christoph S Werner, Hans Zappe, K Buse, Ingo BreunigAbstract:Adiabatic frequency conversion has some key advantages over nonlinear frequency conversion. No threshold and no phase-matching conditions need to be fulfilled. Moreover, it exhibits a conversion efficiency of $100\,\%$ down to the single-photon level. Adiabatic frequency conversion schemes in microresonators demonstrated so far suffer either from low quality factors of the employed resonators resulting in short photon lifetimes or small frequency shifts. Here, we present an adiabatic frequency conversion (AFC) scheme by employing the Pockels Effect. We use a non-centrosymmetric ultrahigh-$Q$ microresonator made out of lithium niobate. Frequency shifts of more than $5\,$GHz are achieved by applying just $20\,$V to $70$-micrometer-thick crystal. Furthermore, we demonstrate that already with the same setup positive and a negative frequency chirps can be generated. With this method, by controlling the voltage applied to the crystal, almost arbitrary frequency shifts can be realized. The general advances in on-chip fabrication of lithium-niobate-based devices make it feasible to transfer the current apparatus onto a chip suitable for mass production.
Takayoshi Kobayashi - One of the best experts on this subject based on the ideXlab platform.
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giant Pockels Effect in an electrode water interface for a liquid light modulator
OSA Continuum, 2019Co-Authors: Daisuke Hayama, Shunpei Yukita, Takayoshi Kobayashi, Keisuke Seto, Kyohei Yamashita, Eiji TokunagaAbstract:We report the development of a light modulator using the Pockels Effect of water in a nanometer-thick electric double layer on an electrode surface. The modulator comprises a transparent-oxide electrode on a glass substrate immersed in an aqueous electrolyte solution. When an optical beam is incident such that it is totally reflected at the electrode-water interface, the light is modulated at a specific wavelength with a near-100% modulation depth synchronized with the frequency of the applied AC voltage. This result was reproduced by a calculation that assumes a change in the refractive index of −0.1 in a 2-nm electric double layer and of −0.0031 in a 30-nm space-charge layer formed at the interface between the electrolyte aqueous solution and the transparent electrode. This is the first report of an optical modulator that uses the interfacial Pockels Effect of a material that does not allow for the Pockels Effect in the bulk. The principle of giant optical modulation is explained by invoking the large Pockels coefficient of interfacial water and a Fabry–Perot-resonance Effect in the transparent thin-film electrode.
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Mechanisms of the anomalous Pockels Effect in bulk water
Optical Review, 2018Co-Authors: Shunpei Yukita, Yuto Suzuki, Naoyuki Shiokawa, Takayoshi Kobayashi, Eiji TokunagaAbstract:The “anomalous” Pockels Effect is a phenomenon that a light beam passing between two electrodes in an aqueous electrolyte solution is deflected by an AC voltage applied between the electrodes: the deflection angle is proportional to the voltage such that the incident beam alternately changes its direction. This phenomenon, the Pockels Effect in bulk water, apparently contradicts what is believed in nonlinear optics, i.e., macroscopic inversion symmetry should be broken for the second-order nonlinear optical Effect to occur such as the first-order electro-optic Effect, i.e., the Pockels Effect. To clarify the underlying mechanism, the dependence of the Effect on the electrode material is investigated to find that the Pockels coefficient with Pt electrodes is two orders of magnitude smaller than with indium tin oxide (ITO) electrodes. It is experimentally confirmed that the Pockels Effect of interfacial water in the electric double layer (EDL) on these electrodes shows an electrode dependence similar to the Effect in bulk water while the Effects depend on the frequency of the AC voltage such that the interfacial signal decreases with frequency but the bulk signal increases with frequency up to 221 Hz. These experimental results lead to a conclusion that the beam deflection is caused by the refractive index gradient in the bulk water region, which is formed transiently by the Pockels Effect of interfacial water in the EDL when an AC electric field is applied. The refractive index gradient is caused by the diffuse layer spreading into the bulk region to work as a breaking factor of inversion symmetry of bulk water due to its charge-biased ionic distribution. This mechanism does not contradict the principle of nonlinear optics.
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Giant Pockels Effect of polar organic solvents and water in the electric double layer on a transparent electrode
RSC Adv., 2017Co-Authors: Hironori Kanemaru, Shunpei Yukita, Takayoshi Kobayashi, Hajime Namiki, Yugo Nosaka, Eiji TokunagaAbstract:The Pockels Effect of polar organic solvents and water within the electric double layer (EDL) on an indium–tin–oxide (ITO) electrode is studied to find that water has the largest Pockels coefficient (230 pm V−1), followed in order by methanol (200 pm V−1), ethanol (84 pm V−1), and dimethyl sulfoxide (DMSO) (20 pm V−1). Electrolyte solutions of water and methanol have nearly the same magnitude of Pockels coefficient, while ethanol and DMSO solutions exhibit two and ten times smaller Pockels coefficients than the methanol solution, respectively. The Pockels coefficient scales well with the hydrogen-bond strength (or average cluster size) divided by the solvent viscosity. This suggests that hydrogen bonding and viscosity play crucial roles in the mechanism of the Pockels Effect of these liquids.
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anomalously large electro optic Pockels Effect at the air water interface with an electric field applied parallel to the interface
Applied Physics Letters, 2016Co-Authors: Yuto Suzuki, Shunpei Yukita, Takayoshi Kobayashi, Kengo Osawa, Eiji TokunagaAbstract:The optical Pockels Effect was observed at the air-water interface by electromodulation spectroscopy. When an AC electric field of frequency f was applied parallel to a water surface between Pt electrodes, the field induced a change in the transmitted light intensity synchronized at 1f proportional to the field strength. The 1f signals dominated over 2f signals by one order of magnitude and the signal disappeared when the electrodes were completely immersed under the water surface, strongly suggesting that the observed phenomena were due to the Pockels Effect at the air-water interface. The Pockels coefficient was estimated to be |r|= 1.4 × 105 pm/V, which is much larger than that at the solid-water interface. However, this is unusual because the parallel electric field does not induce the break in inversion symmetry required for the appearance of the Pockels Effect. The electrowetting Effect was experimentally ruled out as a mechanism for the Pockels Effect, and this made the existence of a field perpend...
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deflection switching of a laser beam by the Pockels Effect of water
Applied Physics Letters, 2012Co-Authors: Shunpei Yukita, Naoyuki Shiokawa, Takayoshi Kobayashi, Hajime Namiki, Hiroki Kanemaru, Eiji TokunagaAbstract:Deflection of a laser beam in response to an electric field was detected with a Sagnac interferometer. A laser beam was aligned to travel between two electrodes immersed in aqueous electrolyte solution. When the alternating electric field was applied perpendicular to the beam axis, the direction of the beam deflection was switched synchronously with the field alternation as expected for the Pockels Effect. Broken inversion symmetry is prerequisite to the linear electrooptic Effect, but surprisingly the Effect was observed even when the laser beam travels through the bulk water a few millimeters away from the electrode surface.
