The nonlinear optical (NLO) properties of conjugated azo-based iminopyridine complexes with zinc and silver metal cations were studied. The processes of second and third harmonic generations in ...guest-host polymeric films were investigated and NLO parameters were extracted. Obtained second and third order NLO susceptibilities of zinc containing complex exceeds the latter of silver containing one. Using the Z-scan technique the NLO refractive index, NLO absorption coefficient, second order hyperpolarizability and NLO absorption cross section for the azo-based iminopyridine zinc (II) and silver (I) complexes were obtained and analyzed. Estimated nonlinearity/loss figure of merit of these complexes show promise for optical device applications.
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•Azo-based iminopyridine complexes with zinc and silver metal cations were studied.•Zinc containing complex owns higher NLO susceptibilities than silver containing one.•The complexation by zinc or silver cation enhances the NLO response of the complex.
► We studied organometallic complexes in form of thin films. ► X-ray diffractometry revealed partly crystalline structure. ► Ellipsometry proved thickness decrease under heating. ► 2D X-ray ...diffractograms were recorded and new crystalline arrangement found. ► Orientation of crystallographic planes depended on compounds chemical composition.
Alkynyl-ruthenium based azo-organometallics were studied in form of powders and thin layers obtained by conventional spin coating from solution. X-ray diffractometry revealed partly crystalline structure of powders while corresponding films were amorphous. Next, the films were subjected to a programmed heating and cooling. Meanwhile, their optical properties were monitored in situ using spectroscopic ellipsometry. It was found that upon thermic treatment films spontaneously adopted a crystalline structure, different from previously observed in the case of starting powders. This structure depended on chemical composition of a particular alkynyl-ruthenium compound.
•New approach for fabrication of quality thin film of perovskites was demonstrated.•Nonlinear optical properties were investigated using a Z-scan technique.•Nonlinear optical parameters (β, n2, γ and ...χ(3)) of the perovskites were estimated.•CH3NH3PbBr3 perovskite has large nonlinear optical properties.
The nonlinear optical response of CH3NH3PbBr3 perovskites is investigated using Z-scan technique, employing 10ns laser pulses, at 532nm. The systems were found to exhibit strong nonlinear optical response, dominated by nonlinear refraction. The effect of organic and inorganic composition ratio on the nonlinear susceptibility is studied experimentally. In all cases, the nonlinear absorption and refraction have been determined. The corresponding third-order susceptibilities and second-order hyperpolarizability are determined to be as large as 10−6(esu) and 10−28(esu) under ns laser excitation respectively. Showing large third-order optical nonlinearity in CH3NH3PbBr3 thin films, suggesting their potential for photonics applications.
In this paper we report on synthesis and sensing properties of novel thiophene derivatives representing typical push-pull molecules with D-π-A structure. As an electron-donating group we used ...benzothiophene and various positions of cyano and nitro groups as an acceptor moiety. All compounds exhibit profound solvatochromism with prominent emission varying from blue to red, which indicated high sensitivity to environment polarity. Moreover, even trace amounts of protic solvents (like water and alcohols) are able to significantly quench the luminescence, with the detection limit established to 59 ppm in THF. On the other hand, the dicyanovinyl group presented in one of the compounds made it an extremely sensitive colorimetric and fluorescent sensor for cyanide and hydroxide ions, shifting its emission towards shorter wavelengths. The detection limits for CN− and OH− were established as low as 0.0131 μM and 0.0025 μM, respectively, which is one of the lowest limit reported in literature. Highly-precise sensitivity to water, alcohols and dangerous ions put such thiophene derivatives as easy-to-use and fast detector in everyday life.
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•Sensing properties of novel thiophene derivatives representing typical push-pull molecules with D-π-A structure are shown.•All compounds exhibit profound solvatochromism with prominent emission varying from blue to red.•Trace amounts of protic solvents are able to quench the luminescence, with the detection limit established to 59 ppm.•The dicyanovinyl group made it an extremely sensitive colorimetric and fluorescent sensor for cyanide and hydroxide ions.•The detection limits for CN- and OH- were established as low as 0.0131 μM and 0.0025 μM.
The optimal geometries of vector phase matching are determined for the cases of second harmonic, sum and difference frequency generation in often-used uniaxial nonlinear optical crystals – KDP, ...ZnGePe2, GaSe, LiIO3, LiNbO3, BBO. The directions of wave vectors ensuring the highest possible efficiency of generation are defined by the extreme surfaces method. As it is shown, in a significant number of cases, the vector phase matching ensures higher efficiencies than the scalar one.
•The extreme surfaces technique is used for study of non-linear optical effects.•Vector phase matching in uniaxial non-linear optical crystals is considered.•The maxima of efficiency of non-linear optical interactions are determined.•The algorithm to plot the extreme surfaces for non-linear optical effects is given.•In many cases vector phase matching ensures higher efficiencies than the scalar one.
The presented work concerns computational investigations of the physical properties of composite materials based on polymer matrix and nonlinear optical (NLO) active chromophores. The structural, ...electronic, and optical properties of selected tetrathiafulvalene (TTF)-based chromophores have been calculated using quantum chemical methods. The polymer matrix changes the physical properties of the inserted chromophores influencing their optical parameters. To explain the mechanism of the NLO signal occurrence from the composites based on poly(methyl methacrylate) (PMMA) matrix and TTF chromophores, their structures are modeled using the classical molecular dynamics. In consequence, the structural properties of the composites are discussed according to the NLO requirements. By developing the theoretical model based on a discrete multipole local field approach, the impact of polymer matrix on the optical properties of chromophores is explained.
Water quality monitoring is an important part of environmental protection, and the ability to qualitatively and quantitatively determine the level of impurities in water is especially important. ...Laser-induced breakdown spectroscopy (LIBS) has become a promising technique compared with the currently available water quality control methods. LIBS has several advantages, including minimal or no sample pre-treatment, fast and easy operation, and a chemical-free process. This article reviews the studies conducted on LIBS analysis for the detection of heavy metals in water samples. The article describes a historical perspective at the progress of LIBS, the LIBS instrumentation, LIBS procedures without pre-treatment and different pre-treatment methods of aqueous samples for improving the limit of detection (LOD), quantitative analysis of metallic elements in liquids, LIBS signal enhancement methods and data processing, characteristics of plasma generated by laser in water, improving the LIBS sensitivity for the detection of trace heavy metals in aqueous solutions, factors affecting the accuracy of the analysis results, and LIBS spectra after measurements. This review will help readers better understand the LIBS technique for detecting heavy metals in liquids and identify current research requirements for environmental water quality monitoring.
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•LIBS analysis of heavy metals in water is presented.•Pre-treatment methods for LIBS signal improvement are characterised.•LIBS enhancement techniques for increasing limits of detection are discussed.•Factors affecting LIBS in aqueous samples are considered.•LIBS spectra after measurements are analysed.
The optical properties of cyanine-based compounds are determined by single molecules as well as the dimers and aggregates formed. In our work, we show the influence of the molecular structure of the ...dye, through the use of modified cyanine derivatives, both on the negative solvatochromic effect and on a tunable, two-band lasing coming from the vibrational states of the molecules. Thus, we demonstrate the dependence of the dye form on optical properties, including nonlinear optical ones.
•Extension of the side chain of cyanine derivatives red-shifts the lasing emission.•α-CD facilitates encapsulation of the dye into the cut cone structure and enables laser emission from a selective dye forms.•Independent random lasing signal from two different forms of the cyanine dyes was observed.•Selected cyanine derivatives maintain centrosymmetric structure, for different forms of dye.
The synthesis of high-quality thin films through spin coating deposition on meticulously cleaned glass substrates is presented. Optical band gaps E g of both samples using the Kubelka–Munk function ...are determined. The data analysis uncovers the presence of optical allowed direct transition for A 2 ZnGeO 4 (A = K, Li). Spectroscopic ellipsometry measurements on A 2 ZnGeO 4 (A = K, Li) thin films and an analysis of their optical properties using the Cauchy model are presented. Furthermore, the increase of the thickness of the thin film results in improvements in their optoelectrical parameters, such as electrical conductivity, optical mobility, and optical conductivity. Using the Kubodera and Kobayashi comparative model, the third order nonlinear susceptibility ( χ (3) ) was estimated based on the compounds' high linear absorption of the generated third harmonic wavelength (355 nm). This paper presents remarkable NLO results that reveal potential uses in optoelectronics and photonics.
An optical control of many working optoelectronic systems (real-time sensors, optical modulators, light amplifiers, or phase retarders) giving efficient optical gain or remote signal modulation is ...currently included as scientifically and industrially interesting. In here, an oxazolone derivative as the multifunctional organic system is given in this contribution. The molecule possesses a stilbene group and an oxazolone heteroatomic ring, which implies effective refractive index manipulation and multimode lasing action, respectively. The light modulation is repeatable and stable, also in the hundreds of Hz regime. On the other hand, the amplified optical signal can be easily generated by an external optical pumping source. Thus, signal control is fully available, as is read-in and read-out of the information in real time. Furthermore, this third-order, nonlinear, optical phenomenon using a third harmonic generation technique was also observed. We discovered that only by changing the energy and time regime of the supplied optical signal is the optical or nonlinear optical response observed. Two heteroenergetic molecular states (trans (E) and cis (Z)) can efficiently operate in modern multifunctional optoelectronic systems, which can provide and generate an optical signal. Such functionalities are commonly used in all-optical photonic switchers and logic gates and can be utilized in optical-core networks and computers.
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