Nonlinear optical properties of organic and polymeric materials
29 Sep 1983-
About: The article was published on 1983-09-29 and is currently open access. It has received 762 citations till now.
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TL;DR: In this paper, second-order nonlinear optical copolymers containing p-hydroxyphenyl maleimide or 4-cinnamoyloxy-phenylmaleimide as a comonomer were newly synthesized.
Abstract: Second-order nonlinear optical copolymers containing p-hydroxyphenyl maleimide or 4-cinnamoyloxy-phenylmaleimide as a comonomer were newly synthesized. For improving the temporal stability, we adopted the crosslink reaction thermally and photochemically. Second-order nonlinear optical properties of the poled/cured films were investigated in terms of the second harmonic generation (SHG) and linear electro-optic (EO) coefficient measurement. SHG coefficient, d33 was found to be 14 pm/V at the fundamental wavelength of 1064 nm and EO coefficient, r33 was found to be 25–30 pm/V at 633 nm wavelength in two different crosslinked structures. To prevent the orientational relaxation of poled polymer, thermal crosslink reaction was induced using diisocyanate as a crosslinker between the side chains themselves. Another photo-crosslink was induced exposing the film at 257 nm wavelength during poling. Temporal stabilities of second-order NLO coefficients of crosslinked polymer systems were proved much better ...
16 citations
TL;DR: In this paper, an optically good quality semiorganic single crystal of l-threoninium phosphate (LTP) was grown by solvent evaporation technique at room temperature.
Abstract: An optically good quality semiorganic single crystal of l-threoninium phosphate (LTP) was grown by solvent evaporation technique at room temperature. Single and powder XRD revealed the orthorhombic crystal structure of LTP with non-centrosymmetric space group Pna21. Linear optical behaviour of the title crystal was realized using UV–visible spectroscopy. The lower cut-off value was found to be 200 nm with broad optical transparency in entire visible region. Functional group and its bonding nature in the titular compound are explored by FTIR spectroscopic analysis. The LTP is thermally stable up to 241 °C and deferent level of decompositions with respect to temperature was analyzed using TG/DTA. Mechanical properties of LTP were studied using Vickers’ microhardness tester. The fracture toughness (Kc), Knoop hardness (Hk), brittleness index (Bi) and elastic stiffness constant (C11) of LTP were calculated using micro-indentation data. Laser damage threshold value of LTP was found to be 4.92 GW/cm2 which is convincingly high to use the crystal in lasing applications. The second harmonic generation efficiency of LTP is 2.1 times greater than the conventional KDP crystal. The nonlinear refractive index (n2), the nonlinear absorption coefficient (β) and third-order nonlinear susceptibility (χ(3)) of the title crystal was found to be 1.19 × 10−15 m3/W, 4.742 × 10−9 m/W and 5.382 × 10−14 m/W (esu) respectively. The single beam Z-Scan unit equipped with 532 nm continues wave laser was used to measure the third-order nonlinear optical parameters of grown crystal.
16 citations
TL;DR: In this article, two new homologous series viz 1-(4′-butyloxybiphenyl-4-yl)-3-(4-alkoxyphenyl) prop-2-en-1-one (Series-I) and 4-[3]-butyloxyprop-1]-naphyl 4-alkoxybenzoate (series-II) were synthesized having the chalcone as a central linkage.
Abstract: Mesogens with a chalcone central linkage are rare It is believed that the chalcone linkage is not conducive to mesomorphism But when chalcone linkage is present with other central linkages like azomethine, ester or azo it becomes condusive to mesomorphism In the present study two new homologous series viz 1-(4′-butyloxybiphenyl-4-yl)-3-(4-alkoxyphenyl) prop-2-en-1-one (Series-I) and 4-[3-(4′-butoxybiphenyl-4-yl)-3-oxoprop-1-en-1-yl] phenyl 4-alkoxybenzoate (Series-II) were synthesized having the chalcone as a central linkage Series-I having only chalcone central linkage through it exhibit mesomrphism due to the presence of alkoxy biphenyl group at one end which is rich source to provide to increase linearity and rigidity of the molecule Series-II which contains chalcone as well as ester as a central linkage and it also exhibit mesomorphism The compounds of the both series have been characterized by standard methods Their liquid crystalline properties have been investigated by optical polarizing mi
16 citations
TL;DR: In this paper, a new organic nonlinear optical (NLO) single crystal of thiosemicarbazide-4-hydroxybenzenesulfonate Monohydrate (THBSM) was successfully synthesized and single crystals were grown by slow evaporation solution growth technique (SESGT).
Abstract: A new organic non-linear optical (NLO) single crystal of thiosemicarbazide-4-hydroxybenzenesulfonate Monohydrate (THBSM) was successfully synthesized and single crystals were grown by slow evaporation solution growth technique (SESGT). The single crystal X-ray diffraction studies confirm that the grown crystal crystallizes in monoclinic system with P21/n space group. The asymmetric part of the title crystal contains isolated thiosemicarbazide cation, 4-hydroxybenzesulfonate anion and a water molecule. Thereby, interplay between vast number of intermolecular interactions such as N–H⋯S, N–H⋯O, C–H⋯O, O–H⋯O and O–H⋯S hydrogen bonds are taken for discussion. FT-IR spectral analysis showed the vibrational behaviour of chemical bonds and presence of its functional groups. UV–Vis–NIR spectral analysis reveals that the optical transparency of THBSM is more than 90% in the entire Vis–NIR region, which confirms its colourless nature and suitable candidate for applications in optoelectronic devices. Photoluminescence (PL) spectrum exhibits a sharp and broad emission peak at centered at 415 nm indicates violet emission. Thermal stability and melting point of the titular compound were studied by TG-DSC analysis. The low value of the dielectric constant of THBSM suggests that the crystal can be used in the microelectronics industry. Third-order nonlinear optical parameters of the title crystal were studied by the single beam Z-scan technique at 632.8 nm using a He–Ne laser as a source. Moreover it exhibits strong reverse saturable absorption (RSA) and a self-focusing nature with large second-order hyperpolarizability (γ = 7.304×10−34 esu), which are mainly associated with electronic processes. From the analyzed results, it is clear that the title crystal possesses excellent third-order nonlinear optical (TONLO) properties and it is suitable for all optical switching, optical limiting and photonic applications.
16 citations
Cites background from "Nonlinear optical properties of org..."
...New organic nonlinear optical (NLO) materials have become increasingly important and attracts more and more attention owing to their promising applications in a telecommunications system, optical computing, optical information processes, optoelectronics, photonics, laser science and technology [1, 2]....
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15 Jan 2001
TL;DR: SHG (second harmonic generation) interferometry and linear dichroism measurements were applied to the characterization of Langmuir-Blodgett monolayers composed of rhodamine B derivatives on hydrophilic fused silica substrates and a unique phenomenon was observed.
Abstract: SHG (second harmonic generation) interferometry and linear dichroism measurements were applied to the characterization of Langmuir-Blodgett monolayers composed of rhodamine B derivatives on hydrophilic fused silica substrates. When excited with a Nd-YAG laser, the contribution of dimeric species composed of rhodamine B chromophores to the nonlinear optical behavior was large, even though the relative concentration of the dimers was small. This implies the formation of noncentrosymmetrically oriented dimers with a relatively higher nonlinear molecular susceptibility, beta. Therefore, a unique phenomenon was observed; that is, the relative phase of the SH light shifted depending on the incident light polarization (p and s). In addition, it was found that the relatively standing up orientation was favored for the dimer, while a strongly tilted orientation was favored for the monomer. Copyright 2001 Academic Press.
16 citations