scholarly journals THE EFFECT OF THE SUBSTITUENT NATURE IN THE AZOBENZENE CHROMOPHORES ON DIFFRACTION EFFICIENCY OF POLARIZATION HOLOGRAMS

2019 ◽  
pp. 30-33
Author(s):  
M. Davidenko ◽  
I. Davidenko ◽  
V. Kravchenko ◽  
O. Mokrinska ◽  
V. Pavlov ◽  
...  
Keyword(s):  
Diffraction Efficiency ◽  
Optical Anisotropy ◽  
Polarized Light ◽  
Mutual Orientation ◽  
Polarization Holography ◽  
Light Modulators ◽  
Linearly Polarized ◽  
Light Beams ◽  
Plane Wave Front ◽  
Azobenzene Groups

The films of polymeric composites containing monomers of azobenzene dyes or azobenzene lateral groups chemically bonded to the main polymer chain demonstrate photoactive properties, and can be used in electrooptical light modulators and in recording media (RM) for polarization holography. Photoinduced optical anisotropy (PIA) appears under influence of linearly polarized light caused by the processes of trans-cis-izomerization of the azobenzene groups. This process is determining for application of the considered materials as RM for polarization holography. The films of polymeric polarization sensitive media based on a copolymer of styrene with nonyl methacrylate doped with azobenzene-type dyes with different electron-acceptor substituents are obtained in this work. In the films of copolymer the holograms of the plane wave front were registered for parallel and orthogonal orientations of polarization vectors of the object and reference light beams. Their photoelectrophysical, in particular photodielectric, and information properties are investigated. It was established, that when the mutual orientation of the recording beams changes from the orthogonal to parallel orientation the diffraction efficiency of the holograms increases in the case of using azo dye with the maximum number of auxochromic substituents in the molecule. The effect of the diffraction efficiency dependence on the chromophores structure is connected with the deepening of dye color. The photo-induced optical anisotropy in the films appears due to a change of the concentration ratio of trans- and cis-isomers of azobenzene dye fragments. This conclusion is confirmed by the photodielectric measurements data, namely, by the negative sign of the photodielectric effect, observed experimentally in the investigated thin film structures. It was shown, that investigated compositions can be used as information media for polarization holography.

Properties of Epitaxial ZnO Thin Films for GaN and Related Applications

1998 ◽  
Vol 537 ◽  
Author(s):  
H. Shen ◽  
M. Wraback ◽  
J. Pamulapati ◽  
S. Liang ◽  
C. Gorla ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Anisotropy ◽  
Polarized Light ◽  
Chemical Vapor ◽  
Zno Thin Films ◽  
Organic Chemical ◽  
Zno Films ◽  
Light Modulator ◽  
Cross Sectional ◽  
Linearly Polarized

AbstractIn this paper, we present a detailed study of high quality (110) ZnO films, epitaxially grown on R-plane sapphire substrates by metal-organic chemical vapor deposition (MOCVD). The epitaxial relationships are (1120) ZnO//(0112) Al2O3 and {0001} ZnO//[0111] A12O3 as confirmed by X-ray diffraction (θ-2θ, and φ-scan) and high-resolution cross-sectional transmission electron microscopy (HR-TEM). Low temperature photoluminescence (PL) indicates the ZnO thin films are almost strain free. Optical absorption and reflection measurements with linearly polarized light indicate a strong optical anisotropy. The polarization rotation towards the C-axis associated with the optical anisotropy is utilized to demonstrate an optically addressed ultra-fast, ultraviolet light modulator.

scholarly journals Non-orthogonal polarization multiplexed metasurfaces for tri-channel polychromatic image displays and information encryption

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Renyuan Ren ◽  
Zile Li ◽  
Liangui Deng ◽  
Xin Shan ◽  
Qi Dai ◽  
...  
Keyword(s):  
Polarized Light ◽  
Orthogonal Polarization ◽  
Image Encoding ◽  
Information Encoding ◽  
Independent Information ◽  
Linearly Polarized ◽  
Image Displays ◽  
Polarization States ◽  
Light Beams ◽  
Channel Image

Abstract Interference usually occurs between two non-orthogonally polarized light beams. Hence, metasurface enabled polarization multiplexing is generally conducted under two orthogonal polarization states to realize independent intensity and/or phase modulations. Herein, we show that polarization multiplexed metasurfaces can work under three non-orthogonal polarization states to realize tri-channel image displays with independent information encoding. Specifically, enabled by orientation degeneracy, each nanostructure of the metasurface operates with triple-manipulations of light, i.e., two channels for independent intensity manipulation under π/4 and 3π/8 linearly polarized (LP) light, respectively, and one channel for phase manipulation without polarization control. We experimentally demonstrate this concept by recording one continuous-brightness polychromatic image and one binary-brightness polychromatic image right at the metasurface plane, while a continuous-brightness polychromatic image is reconstructed in the far field, corresponding to three independent channels, respectively. More interestingly, in another design strategy with separated image encoding of two wavelengths, up to six independent image-display channels can be established and information delivery becomes safer by utilizing encryption algorithms. With the features of high information capacity and high security, the proposed meta-devices can empower advanced research and applications in multi-channel image displays, orbital angular momentum multiplexing communication, information encryption, anti-counterfeiting, multifunctional integrated nano-optoelectronics, etc.

Characterization and photoinduced properties of photo chromic polymers. 1. Polyesterimides with 4-amino 4´-nitro azobenzene moieties

e-Polymers ◽  
2006 ◽  
Vol 6 (1) ◽  
Author(s):  
Ewa Schab-Balcerzak ◽  
Beate Sapich ◽  
Joachim Stumpe ◽  
Anna Sobolewska ◽  
Andrzej Miniewicz
Keyword(s):  
Optical Anisotropy ◽  
Polarized Light ◽  
Ethyl Benzene ◽  
H Nmr ◽  
Azobenzene Group ◽  
Vis Spectroscopy ◽  
Different Types ◽  
Linearly Polarized ◽  
Kinetics Of ◽  
Dsc Thermograms

AbstractNovel photochromic polyesterimides (PEIs) with two different types of azobenzene units as side groups have been synthesized from 2,2’-{4-[(4- nitrophenyl)-azo} phenyl]iminobis(ethyl benzene-1,2-dicarboxylic acid anhydride-4- carboxylate) and diamines: 2,4-diamino-4’-methylazobenzene and 2,4-diamino-4’- (trifluoromethoxy)azobenzene. An analogous polyesterimide with one azobenzene group based on 1,3-phenylendiamine has been prepared to compare with these PEIs. Molecular structural characterization for these polymers has been achieved by FTIR, 1H NMR and UV-Vis spectroscopy. These amorphous polyesterimides are thermally stable up to 260°C as follows from the thermogravimetric analysis (TGA). The glass transition temperatures (Tg) for the resulting polyimides have been determined from DSC thermograms and are in the range of 141-210°C. The irradiation with linearly polarized light of an Ar+ laser results in the induction of optical anisotropy within the initially isotropic films. Light induced optical anisotropy in polymer films has been studied by examining the value of generated dichroism using Ar+ laser (λ = 488 nm) and by holographic polarization grating recording performed at λ = 514.5 nm. The value of photoinduced dichroism is in the range of 0.15-0.26. The induction of dichroism and kinetics of grating inscription have been investigated in relation to the presence of the second type of azobenzene group in the polymer and its substitution.

UNPOLAR AND POLAR HOLOGRAPHIC GRATING RECORDING BY CIRCULARLY POLARIZED LIGHT ON PHOTOANISOTROPIC AZOBENZENE LANGMUIR–BLODGETT FILMS

2003 ◽  
Vol 12 (04) ◽  
pp. 495-511 ◽  
Author(s):  
L. M. BLINOV ◽  
R. BARBERI ◽  
F. CIUCHI ◽  
M. P. DE SANTO ◽  
G. CIPPARRONE ◽  
...  
Keyword(s):  
Probe Beam ◽  
Optical Anisotropy ◽  
Polarized Light ◽  
Spatial Modulation ◽  
Circularly Polarized Light ◽  
Circularly Polarized ◽  
Langmuir Blodgett ◽  
Linearly Polarized ◽  
Langmuir Blodgett Films ◽  
Ion Laser

A comparative study of photo-induced optical anisotropy was carried out on Langmuir–Blodgett films prepared from five different amphiphilic azobenzene derivatives. The anisotropy was induced by a linearly polarized pump beam of an Ar-ion laser at λ=514 nm and monitored by a linearly polarized probe beam of a He–Ne laser at λ=633 nm . Large optical anisotropy up to 0.35 has been induced. Holographic gratings were recorded by two left circularly polarized beams of the Ar-ion laser and time evolution of the first-order diffraction efficiency of the probe beam was recorded in an automatic regime. In such a geometry, the spatial modulation of refraction index reaches 0.14. The experimental data is consistent with a model for a photo-induced collective chromophore realignment in the heterogeneous domain structure of the films studied. The influence of an electric field of the corona discharge on the grating recording process was also studied and polar diffraction gratings have been prepared by a spatially periodic photo-poling process.

scholarly journals Generation of the tunable vector ellipse hollow beam by using linearly polarized light beams

2014 ◽  
Vol 63 (8) ◽  
pp. 083701
Author(s):  
Chen Guo-Jun ◽  
Zhou Qiao-Qiao ◽  
Ji Xian-Ming ◽  
Yin Jian-Ping
Keyword(s):  
Polarized Light ◽  
Hollow Beam ◽  
Linearly Polarized ◽  
Light Beams

scholarly journals Влияние поляризации считывающей волны и циркулярного дихроизма на дифракционную эффективность отражательной голограммы в кубическом оптически активном фоторефрактивном поглощающем пьезокристалле

2021 ◽  
Vol 129 (1) ◽  
pp. 66
Author(s):  
В.Н. Навныко ◽  
В.В. Шепелевич ◽  
С.М. Шандаров
Keyword(s):  
Circular Dichroism ◽  
Diffraction Efficiency ◽  
Polarized Light ◽  
Crystal Thickness ◽  
Light Waves ◽  
Linearly Polarized ◽  
Reflection Hologram ◽  
Phase Amplitude ◽  
Circular Dichroïsm ◽  
Phase Reflection

In the approximation of slowly varying amplitudes, a system of coupled waves equations is obtained, which is applicable for describing the diffraction and coupling of elliptically polarized light waves on a volume phase-amplitude holographic grating formed in a cubic optically active photorefractive absorbing piezoelectric crystal. The dependence of the diffraction efficiency of the phase reflection hologram on the ellipticity of the readout wave and the thickness of the Bi12SiO20 crystal of the (001) and (111) cuts was studied. The regularities of the effect of circular dichroism on the diffraction efficiency of the phase reflection hologram are analyzed. It is shown that for crystal of (001)-cut the maximum diffraction efficiency of the reflection hologram depending on the crystal thickness can be achieved using a readout wave both with linear polarization and with elliptical polarization. For crystal of (111)-cut the highest diffraction efficiency is achieved using a linearly polarized readout wave. It has been established that the effect of circular dichroism on the intensity of the reconstructed wave depends on the cut of the crystal, the ellipticity of the readout wave and the thickness of the crystal.

scholarly journals Reflection Band Control of Inverse Opal Film with Photoresponse Properties of Push-Pull Type Azobenzene LC Polymers

2008 ◽  
Vol 2008 ◽  
pp. 1-5
Author(s):  
Sunnam Kim ◽  
Takahiro Shiozawa ◽  
Masaki Moritsugu ◽  
Tomonari Ogata ◽  
Takamasa Nonaka ◽  
...  
Keyword(s):  
Bragg Reflection ◽  
Polymer System ◽  
Polarized Light ◽  
Wavelength Region ◽  
Inverse Opal ◽  
Reflection Band ◽  
Linearly Polarized ◽  
Photo Response ◽  
The Relationship ◽  
Azobenzene Groups

DcAz2Mc and DR1Mc molecules having push-pull type of azobenzene groups are synthesized, and their photo-orientational behaviors are investigated in the polymer system. In order to understand the relationship between a molecular structure and its physical properties, electronic structure calculation is computationally carried out. Regarding to their photo response properties, the copolymers ofpoly(DcAz2Mc-co-M6PBMe) andpoly(DR1Mc-co-M6PBMe) are infiltrated into inverse opal films, and Bragg reflection shifts are observed under photostimuli. When the linearly polarized light is irradiated, Bragg reflection bands are shifted to the longer wavelength region as reflective index increases.

scholarly journals Linearly Polarized UV Light-Induced Optical Anisotropy of PVA Films and Flexible Macrocycle Schiff Base Ni(II), Cu(II), Zn(II) Dinuclear Complexes

Symmetry ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 760
Author(s):  
Masahiro Takase ◽  
Shiomi Yagi ◽  
Tomoyuki Haraguchi ◽  
Shabana Noor ◽  
Takashiro Akitsu
Keyword(s):  
Optical Anisotropy ◽  
Molecular Orientation ◽  
Soft Matter ◽  
Uv Light ◽  
Polarized Light ◽  
X Ray ◽  
Crystallographic Symmetry ◽  
Linearly Polarized ◽  
Dinuclear Metal Complexes ◽  
Crystal Structural

Three dinuclear metal complexes (comprised of six-coordinated nNi2L and five-coordinated nCu2L and nZn2L) were confirmed by means of elemental analysis, UV-vis and IR spectra, and single X-ray crystal structural analysis in a spectroscopic study. The stable structures of these nNi2L, nCu2L, and nZn2L complexes in poly(vinylalcohol) (PVA) films were analyzed using UV-vis spectra. The molecular orientation of hybrid PVA film materials after linearly polarized light irradiation was analyzed to obtain the polarized spectra and dichroic ratio. Among the three materials, nNi2L and nZn2L complexes indicated an increasing optical anisotropy that depended on the flexibility of the complexes. We have included a discussion on the formation of the pseudo-crystallographic symmetry of the components in a soft matter (PVA films).

RESULTS OF POLARIZED LIGHT USE FOR STUDY OF STRESS-STRAIN STATE OF CORNEA IN PATHOLOGY OF EXTRAOCULAR MUSCLES

2020 ◽  
pp. 65-69
Author(s):  
Nataliia Mykhailivna Kovtun ◽  
Ihor Volodymyrovych Kaplin
Keyword(s):  
Interference Pattern ◽  
Optical Anisotropy ◽  
Extraocular Muscle ◽  
Strain State ◽  
Polarized Light ◽  
Attachment Site ◽  
Rectus Muscle ◽  
Extraocular Muscles ◽  
Asymmetric Distortion ◽  
Interference Picture

The parameters of interference patterns observed on the cornea in a polarized light in pathology of extraocular muscles were quantitatively evaluated. A study of the shape of 147 interference patterns observed on the cornea in a polarized light showed that the horizontal deviation of an eye in 56 % of cases was caused by the displacement of the attachment of the upper rectus muscle towards the inner rectus muscle. During illumination of the cornea of a live eye with polarized light, a specific interference pattern in the form of a rhombus formed by rainbow stripes (isochromes) is observed. It is established that such an interference pattern is the result of the influence of extraocular muscles on the cornea. The findings showed that the weakening of the force of one of muscles leads to asymmetric distortion of the shape of the interference rhombus, which is manifested with a reduced length of the corresponding section of the diagonal. On the contrary, as the force of the muscle increases, the corresponding section of the diagonal enhances. The displacement of the attachment site of direct extraocular muscle along the line of action is equivalent to a change in effort on its part, indicated appropriately by the shape of the interference rhombus. As the muscle moves away from the line of action, the angle of the interference rhombus is shifted away from the corresponding meridian. Key words: polarized light, optical anisotropy, cornea, extra−ocular muscles, interference picture.

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