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Nonlinear Dynamics in Quantum Photonic Structures
Published in Joachim Piprek, Handbook of Optoelectronic Device Modeling and Simulation, 2017
Gabriela Slavcheva, Mirella Koleva
There is a fundamental relationship between chirality and optical activity. The interaction of polarized light with chiral materials gives rise to the phenomenon of optical rotation (or optical activity), whereby the polarization plane is rotated continuously during the propagation of the light through the nanotube. In the presence of an external magnetic field, magnetically induced optical activity—also known as Faraday effect—takes place. Both effects manifest themselves as a rotation of the transmitted light; however, the origin of the two effects is fundamentally different. While the natural optical activity is a result of the nonlocal optical response of a medium lacking mirror symmetry, the magnetic optical activity results from time-reversal symmetry breaking by the magnetic field. The two phenomena are linked through the magneto-chiral optical effect which takes place when both symmetries are broken simultaneously [82].
Polarimetry
Published in Toru Yoshizawa, Handbook of Optical Metrology, 2015
Optical rotation is also called circular birefringence. An optical rotation polarimeter measures the rotation of the polarization plane of a linearly polarized light beam when it passes through a chiral sample. The simplest optical rotation polarimeter is constructed by using a polarizer and a crossed analyzer. The optical rotation is the angular difference in the null positions on the analyzer with and without a chiral sample. Simple optical rotation polarimeters have been used in the sugar industry for nearly two centuries. An optical rotation polarimeter is perhaps the most commonly used special polarimeter in industrial and analytical laboratories. In fact, when people use the term “polarimeter,” most refer to an optical rotation polarimeter.
Some features of magneto-optics of cholesteric liquid crystals
Published in Journal of Modern Optics, 2021
A. H. Gevorgyan, S. S. Golik, N. A. Vanyushkin, A. V. Borovsky, H. Gharagulyan, T. M. Sarukhanyan, M. Z. Harutyunyan, G. K. Matinyan
The optical rotation of the polarization plane occurs due to the difference in the phase velocities of light with right and left circular polarizations. Far from the PBG, the optical rotation in the CLC occurs due to the chiral structure of the CLC. In the PBG, a wave with one circular polarization experiences strong diffraction reflection, while a wave with another circular polarization weakly interacts with the medium; as a result the optical rotation in the CLC in the PBG is much larger than the intrinsic rotation caused by the optical activity of the CLC [46]. In the presence of an external magnetic field, another mechanism of rotation of the polarization plane emerges. So, it is important to study the features of the spectra of the optical rotation and the ellipticity of polarization when linearly polarized light (polarized along the x-axis) is incident on the CLC layer.
The influence of flexible spacer and the chirality of the core on the formation of chiral nematic phase of symmetric dimers containing trifluoromethyl terminal
Published in Liquid Crystals, 2019
Nuclear magnetic resonance hydrogen spectrometer (1H NMR) (600 MHz) and Fourier transform infrared spectroscopy (FTIR) are measured by Varian WH-90PFT NMR Spectrometer (Varian Associates, Palo Alto, CA) and PerkinElmer instruments Spectrum One Spectrometer (PerkinElmer, Foster City, CA), respectively. Differential scanning calorimetry (DSC) measurements are carried out with a TA instruments DSC 25 TA (New Castle, DE, American) at a scanning rate of 20°C min−1 under a flow of dry nitrogen. X-ray diffraction (XRD) measurements are performed with nickel-filtered CuKα (λ = 1.54 Ǻ) radiation with a D8 ADVANCE XRD (Bruker, Karlsruhe, Germany). The X-ray measurements include wide-angle XRD experiments and small-angle X-ray scattering measurements. Measurement of optical rotation (a) is carried out with a PerkinElmer instrument Model 341 Polarimeter at room temperatures using sodium light source (λ = 589 nm). The polarised optical microscopy (POM) study is performed using a Leica DMRX (Leica, Wetzlar, Germany) equipped with a Linkam THMSE-600 (Linkam, Surrey, England) heating stage.
Non-symmetric chiral nematic liquid crystal dimers containing trifluoromethyl and 1,2-propanediol
Published in Liquid Crystals, 2018
Liang Dong, Zhi-xin Xu, He-zhong Tao, Xin-shi Chen, Jian-she Hu, Dan-shu Yao, Mei Tian
1H NMR and FTIR are measured by Varian WH-90PFT NMR Spectrometer (Varian Associates, Palo Alto, CA) and PerkinElmer instruments Spectrum One Spectrometer (PerkinElmer, Foster City, CA), respectively. Differential scanning calorimetry (DSC) measurements are carried out with a NETZSCH instruments DSC 204 (Netzsch, Wittelbacherstrasse, Germany) at a scanning rate of 10°C min−1 under a flow of dry nitrogen. Thermogravimetric analysis (TGA) measurement is carried out with a NETZSCH TGA 209C thermogravimetric analyzer. X-ray diffractometer (XRD) measurements are performed with nickel-filtered Cu Kα (λ = 1.54 Å) radiation with a D8 ADVANCE XRD (Bruker, Karlsruhe, Germany). The X-ray measurements include wide-angle X-ray diffraction experiments and small-angle X-ray scattering measurements. Measurement of optical rotation (a) is carried out with a PerkinElmer instrument Model 341 Polarimeter at room temperatures using sodium light source (λ = 589 nm). The polarised optical microscopy (POM) study is performed using a Leica DMRX (Leica, Wetzlar, Germany) equipped with a Linkam THMSE-600 (Linkam, Surrey, England) heating stage.