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Analysis of measurement of quadratic electro-optic effect in castor oil
(Wydawnictwo Politechniki Łódzkiej, 2013) Izdebski, Marek; Ledzion, Rafał; Kucharczyk, Włodzimierz
This works presents an extended theoretical analysis of the response of experimental setup to an applied electric field during measurements of electro-optic coefficients in optically active liquids using an optical polarimetric technique. The analysis includes liquids belonging to ∞ ∞, ∞ 2 and ∞ Curie symmetry groups and the following phenomena were taken into account: natural optical activity, natural linear birefringence, dichroism, and the effects induced by an applied electric field – linear and quadratic electro-optic effects and linear and quadratic electrogyration. The presented example concerns numerical error analysis for measurement of the quadratic electro-optic effect in castor oil, which exhibits the symmetry ∞ 2 between a pair of plane-parallel electrodes.
Analytical kinetic block model of crystal-mother-phase multilayer interface.
(Wydawnictwo Politechniki Łódzkiej, 2015) Organiściak, Maciej; Izdebski, Marek; Ledzion, Rafał
Simple kinetic block model of multilayer crystal-mother-phase interface is proposed. The model leads to a system of differential equations which can be solved without the need to run Monte Carlo simulations. The proposed model is based on Bragg-Williams approximation (called also zeroth-order approximation), "solid-on-solid" assumption, and other assumptions common with thermodynamic Temkin model. Thus, it is possible to test the compliance of kinetic and thermodynamic approaches in a situation where all other significant differences between models are eliminated. Moreover, a comparison with the results of kinetic Monte Carlo simulations allows for better understanding of the impact of Bragg-Williams approximation.
Application of electrooptic modulators for divergent light beam
(Wydawnictwo Politechniki Łódzkiej, 2009) Izdebski, Marek
Analysis of electrooptic modulators of the light strength working with divergent light beam is performed numerically employing the Jones matrices method. The approach allows to consider small inaccuracies in cutting and alignment of electrooptic crystal and the divergence of entering light beam. The results show that the divergence typical for gas lasers should not affect significantly the work of electrooptic modulators even for large electrooptic crystals, while diode lasers may be used with modulators only in the form of precise modules equipped with colimation optics.
Conductivity in cured epoxy resins containing a biphenyl unit
(Wydawnictwo Politechniki Łódzkiej, 2010) Włodarska, Magdalena; Izdebski, Marek; Bąk, Grzegorz; Mossety-Leszczak, Beata; Galina, Henryk
Conductivity of two epoxy matrices based on the same monomer was compared. The epoxy monomer had symmetric structure and contained the biphenyl group which induced additional phase transitions in the pure material. Two amines responsible for different curing mechanisms were used to prepare the matrices. Wide ohmic regions were observed in both materials but quite high activation energy results in quick drop of conductivity at low temperatures and the materials can be treated as good isolators below 100°C. The obtained results are comparable with traditional epoxy resins.
Electrooptic modulation of light beams deviated far from normal incidence
(Wydawnictwo Politechniki Łódzkiej, 2008) Izdebski, Marek
It is shown that the electrooptic modulation of the phase difference for the light beams propagating oblique through the crystalline plane-parallel plate appears not only as the direct result of the field-induced changes in the refractive indices of refracted waves but also the modulation is due to the changes in the directions and paths lengths of the waves in the crystal. This indirect modulation may become important for light beams deviated significantly from the normal to the entrance and emergence crystal faces. Configurations with the light beams passing oblique through the plane normal to the optic axis are interesting in measurements of the linear electrooptic coefficients r41 and r42 in uniaxial crystals. Although in some crystals symmetries the coefficients r11 or r22 may contribute to phase difference, it is shown that the results obtained for different signs of the incidence angle allow to separate such contribution from that caused by r41 or r42.
Estimations of the magnitude of the fourth-order electrooptic effect in KDP-type crystals
(Lodz University of Technology Press, 2013) Ledzion, Rafał; Izdebski, Marek; Górski, Piotr; Kucharczyk, Włodzimierz
An attempt to measure the fourth-order electrooptic effect in KH2PO4(KDP) and NH4H2PO4(ADP) is presented. Contrary to previously reported results of the order of magnitude 10-30m4V-4, the fourth-order coefficient |g111111- g221111| is found to be lower than 5 · 10-33m4V-4and 1 · 10-34m4V-4, respectively. In addition, the effect of imperfect crystal cutting and alignment is investigated by means of calculations based on Jones calculus. It is found that even small inaccuracies may lead to an apparent fourth-order electrooptic effect comparable in magnitude to the previously reported values.
Frequency dependence of the Kerr constant in nynas nytro 3000 oil determined by the polarimetric method
(Wydawnictwo Politechniki Łódzkiej, 2018) Poborska, Julita; Dąbrówka, Dominika; Chwirot, Maksymilian; Ledzion, Rafał; Izdebski, Marek; Kucharczyk, Włodzimierz
Frequency dependence of the Kerr constant in nynas nytro 3000 oil determined by the polarimetric method A frequency dependence of the Kerr constant K in transformer oil Nynas Nytro 3000 within a frequency range 117-5017 Hz is determined. An averaged value (2.30 ± 0.03)·10ˉ¹⁵ m/V² for K is obtained. The constant is found to be weakly frequency dependent and approaches its maximum 2.37·10ˉ¹⁵ m/V² at about 3000 Hz. The Kerr constant is of comparable value to that observed in other mineral oils employed previously in measurements of the quadratic electro-optic effect and the electrostriction in crystals.
The impact of aromatic additives on kerr effect in rapeseed oil.
(Wydawnictwo Politechniki Łódzkiej, 2015) Komenda, Anna; Górski, Piotr; Ledzion, Rafał; Izdebski, Marek
The Kerr constant and quadratic electro-optic effect were determined for a few different rapeseed oils. The aim of the study was to investigate if aromatic additives in the oil influence its optical properties. Moreover, the effect of ageing of the oils on Kerr phenomena was observed.
Influence of electrode material spacing between electrodes on measurement of Kerr constant in castor oil.
(Wydawnictwo Politechniki Łódzkiej, 2014) Perek, Artur; Ledzion, Rafał; Izdebski, Marek; Nowakowski, Krystian; Górski, Piotr
The influence of the electrode material and of the spacing between electrodes on Kerr constant in castor oil is investigated. It is shown that the spacing of the electrodes influences the measurement of Kerr constant whereas the electrode material has no influence on the results of the measurement.
Modification of Bragg-Williams approximation applied in Jackson's model of crystal growth
(Wydawnictwo Politechniki Łódzkiej, 2010) Izdebski, Marek
Results of Monte Carlo simulations for single-layer solid-fluid interface were compared with Bragg-Williams approximation, which describes the number of bonds between solid and fluid cells in Jackson's crystal growth model. The comparison shows that Bragg-Williams approximation produces much higher values than those resulting from simulations. The use of better approximations based on the results of the simulation does not lead directly to improvement of predictions given by Jackson's model, but rather reveals further problems. In particular, the estimation of entropy seems to be also very overvalued. Monte Carlo simulations were used also to investigate the number of stable states of a single boundary layer for various crystal growth conditions. The results obtained differ significantly from those resulting from the analysis of free energy minima in Jackson's model, but are in good agreement with the results of multi-layer simulations.
Modulation technique used for measurement of very weak linear birefringence and dichroism in liquids on the example of castor oil between metal electrodes.
(Wydawnictwo Politechniki Łódzkiej, 2014) Izdebski, Marek; Ledzion, Rafał
A technique for measurement of very weak linear birefringence of the order of 10-7and dichroism in liquids is proposed. The method is based on the polarimetric technique. A characteristic feature is that the experimental setup enables the measurement of linear birefringence combined with electro-optic effect as well as the measurement of dichroism combined with electro-optic effect. The combination of the effect which does not show rapid changes with the effect which depends on alternating electric field allows to improve the sensitivity of the method (in comparison to the earlier static method). This was achieved by use of lock-in amplifier that measures only the selected harmonic with very high selectivity. The theoretical considerations are illustrated by the results of measurements for castor oil.
On the contribution of the quadratic electrooptic effect to the nonlinear response proportional to the fourth power of modulating field
(Wydawnictwo Politechniki Łódzkiej, 2007) Izdebski, Marek; Kucharczyk, Włodzimierz
It is shown that the fourth-order electrooptic effect cannot be measured without a background of the contribution that is proportional to the square of the quadratic electrooptic coefficient. The contribution manifests on the fourth power of the modulating field and may be calculated. Thus, if the contribution is found to be comparable with the measured fourth-order electrooptic response, this apparent fourth-order effect should be taken into account in the interpretation ofthe results of the measurement.
On the nature temperature dependence of intrinsic quadratic electrooptic coefficients in KDP-type crystals
(Wydawnictwo Politechniki Łódzkiej, 2010) Kucharczyk, Włodzimierz; Ledzion, Rafał; Górski, Piotr; Izdebski, Marek
It is shown that the fourth-order electrooptic effect may be responsible for the temperature dependence of the quadratic electrooptic coefficients defined in terms of polarization. An example is given for the ammonium dihydrogen phosphate (ADP) crystal.
On the possibility of measurements of nonlinear electrooptic effects in 432 symmetry crystals
(Wydawnictwo Politechniki Łódzkiej, 2011) Kucharczyk, Włodzimierz; Górski, Piotr; Izdebski, Marek; Ledzion, Rafał
It is shown that despite the fact that in 432 point group crystals the linear electrooptic effect is vetoed by symmetry there are configurations for which the third-order effect may appear. The results obtained indicate that the 432 crystals are promising media for measurements of nonlinear electrooptic effects. Macroscopic description of nonlinear electrooptic phenomena in the crystals is presented and the matrices of tensors representing the effects up to the fifth-order are given.
Optimization of measurement conditions of Kerr constant in optical active liquids on the example of castor oil.
(Wydawnictwo Politechniki Łódzkiej, 2014) Nowakowski, Krystian; Perek, Artur; Izdebski, Marek; Ledzion, Rafał; Górski, Piotr
The results of measurements of Kerr constant in castor oil, obtained by dynamic-polarimetric method are presented. Variable optical path length and four measurement setup configurations were used. They differed by the orientation of polarizer and of quarterwave plate and therefore they were non-equivalent when other, unwanted effects occurred. It was shown that the Kerr constant measurement performed with use of only one system configuration and one length of optical path may be strongly affected by other effects, however taking the arithmetic mean of two results obtained from appropriate system configurations significantly reduces this error. Theoretical dependences were fitted to the experimental results, which allowed for approximation of other constants, like dichroism, linear birefringence and optical activity induced by external electric field (electrogyration).
Study of electrically induced orientational ordering in mineral oils on the example of orlen oil trafo en.
(Wydawnictwo Politechniki Łódzkiej, 2016) Izdebski, Marek; Adamus, Monika; Jóźwiak, Ewelina; Ledzion, Rafał
A simple model of orientational ordering of molecules in the liquid under the influence of an applied sinusoidal electric field of low frequency is presented. The predicted theoretical dependencies of linear birefringence and light transmission coefficients on the intensity of the applied field were confirmed by experimental data obtained for transformer oil ORLEN OIL TRAFO EN. It was found that the intensity of orientational effects in the oil depends strongly not only on the current conditions, but also on the thermal history of the sample. Furthermore it is shown that the minimum amount of dissolved contaminants (e.g. polyethylene) strongly increases the effects. The results suggest that it is necessary to reconsider the techniques for measuring the Kerr effect in liquids associated with deformation of electron cloud, because the traditional approach does not take into account the orientational effects occurring simultaneously with the Kerr effect.
Temperature dependence of the Kerr constant of fomblin M03.
(Wydawnictwo Politechniki Łódzkiej, 2016) Ledzion, Rafał; Górski, Piotr; Izdebski, Marek; Kucharczyk, Włodzimierz
The Kerr constant B of perfluoropolyether Fomblin M03 has been determined within the temperature range 295-370K. At 300K the constant B was found to be equal to 2.8·10-15 m/V2. The measurements indicate that B varies inversely with temperature. Relatively low electro-optic response of the perfluoropolyether shows its usability in measurements of the quadratic electrooptic effect and the electrostriction in crystals.
Verification of one-dimensional models describing anisotropy of step growth
(Wydawnictwo Politechniki Łódzkiej, 2017) Izdebski, Marek; Ledzion, Rafał
Models that allow to obtain directional dependencies of normal velocity of a straight step on the (001) face of Kossel crystal and its edge free energy are reviewed. The dependencies were considered in a wide range of crystal growth conditions, which showed some significant discrepancies between the models and limitations in the scope of their applicability. The results presented concern on one-dimensional kinetic and thermodynamic models of a single step.
What is the symmetry of castor oil between metal electrodes?
(Wydawnictwo Politechniki Łódzkiej, 2012) Izdebski, Marek; Ledzion, Rafał; Górski, Piotr
Presented experimental data show that castor oil between metal flat electrodes can not be satisfactorily described as an isotropic liquid of ∞ ∞ symmetry, even in the absence of an electric field between the electrodes. Correct description of optical properties requires the assumption of 2 ∞ symmetry and consideration of circular birefringence, linear birefringence and dichroism occurring at the same time. Disappearance of linear birefringence and dichroism in castor oil has been observed several days after filling cuvette witch metal electrodes, which suggests the usefulness of such measurements to study the aging processes. The results presented are also important for correct interpretation of future measurements of electro-optic and electrogyration effects in liquids.