Environment effects on the nonlinear absorption properties of Methylene blue under different power of excitation beam

Solvent Media on Nonlinear Optical Properties of Triarylmethane Dye via Facile Z-Scan Method

Solvent environment on third-order nonlinear optical (TNLO) features of triarylmethane dye namely, basic blue 7 in different solvents is reported herein using 650 nm diode laser with continuous wave mode. The basic blue 7 dye is dissolved in different solvent media including ethanol, methanol, dimethyl formamide (DMF) and dimethyl sulfoxide (DMSO). The influence of solvent characteristics such as solvent polarizability and dipole moment on solute molecule is discussed. TNLO characteristics such as nonlinear optical index of refraction, nonlinear optical coefficient of absorption, real and imaginary components of the TNLO susceptibility are measured to be the order of 10‒7 cm2/W, 10‒3 cm/W, 10‒6 esu and 10‒7 esu, respectively. The dye exhibits large TNLO susceptibility by dissolving in DMSO. The TNLO susceptibility of basic blue 7 dye is measured to be the order of 10‒6 esu. The overall results revealed that the basic blue 7 dye is suitable material for optoelectronics applications.

Extraction of Natural Pigment from Ocimum tenuiflorum Using Different Polar Solvents and Their Nonlinear Optical Characteristics

Herein, we report the extraction, characterization, linear and third-order nonlinear optical (TONLO) features of the natural pigment from Ocimum tenuiflorum leaves using different polar solvents. The polar solvents such as, ethanol, acetone, methanol and dimethyl sulfonate (DMSO) were used to extract the natural pigment from Ocimum tenuiflorum leaves. The effect of solvent on linear and TONLO properties of the natural pigment was studied and multi- parameter scale known as Kamlet-Abboud-Taft was used to analyse the solvent characteristics on solute molecule. The functional groups of the extracted natural pigments were examined via Fourier transform infrared (FT-IR) spectrometer. TONLO characteristics of the natural pigment was scrutinised by a continuous wave (CW) diode laser working at 650 nm wavelength. The nonlinear refractive index (n₂) and nonlinear coefficient of absorption (β) of the natural pigment was ascribed to the behavior of self-defocusing, saturable absorption (SA) and reverse saturable absorption (RSA). The TONLO susceptibility (χ⁽³⁾) of the natural pigment in polar solvents was found to be the order of 10^-6 esu. The natural pigment extracted from Ocimum tenuiflorum leaves is a potential material for applications in nonlinear optical.

Experimental and theoretical investigation on the nonlinear optical properties of LDS 821 dye in different solvents and DNA

Linear and nonlinear optical properties of near-infrared laser grade dye LDS 821 in different solvents and Salmon Deoxyribonucleic acid (DNA) were studied using spectroscopic and Z-scan techniques. UV-Vis absorption spectrum of the dye shows a bathochromic shift with a decrease in the solvent polarity parameter, and in DNA, the dye exhibits a hypochromic shift. The fluorescence spectrum of the dye does not show any notable correlation with the solvent polarity parameter, but in DNA, the fluorescence intensity of the dye decreases with the incremental addition of DNA. Molecular docking studies reveal that the dye intercalates on the major grooves of DNA. Nonlinear optical properties of the dye in different solvents and phosphate buffer solution with varying DNA concentrations were studied using the Z-scan technique using a Q-switched Nd: YAG laser operating at fundamental and second harmonics. A closed and open aperture Z-scan of dye in different solvents was carried out to estimate the nonlinear refractive index, excited-state absorption cross-section, and two-photon absorption coefficient (TPA). The variation in nonlinear optical properties of the dye in different solvents was due to solvent-induced structural modifications. Theoretical investigation on nonlinear optical properties of the dye in different solvents was carried out using density function theory. The theoretical first and second-order hyperpolarizability was calculated using B3LYP functional. The predicated nonlinear optical parameters of the dye in different solvents does not show any direct correlation with solvent polarity. Nonlinear absorption of the dye in phosphate buffer solution (PBS) and DNA were estimated. The nonlinear absorption of the dye in PBS decreases with the addition of DNA. Molecular docking studies were carried out to determine the structural changes induced in dye due to the intercalation with DNA.

Study of Third-order Nonlinear Optical Properties of Basic Violet 3 Dye in Polar Protic and Aprotic Solvents

The present work aims to study of third-order nonlinear optical (TONLO) behavior of basic violet 3 dye dissolved in polar protic and aprotic solvents, namely, ethanol, 1-propanol, acetone and dimethyl sulfonate (DMSO), respectively. The polarity of the solvent used to have a substantial impact on the linear and TONLO properties of the dye sample. The dye exhibits self-defocusing nonlinearity due to thermally induced nonlinear refractive index and nonlinear absorption coefficient reveals the character of both saturable and reverse saturable absorption (RSA). The order of magnitude of nonlinear refractive index (n₂) and nonlinear coefficient of absorption (β) of dye sample was determined to be 10^-7 cm²/W and 10^-3 cm/W, respectively. The real and imaginary factors of the TONLO susceptibility of basic violet 3 dye were measured to be the power of 10^-5 esu. The obtained results reveal that the dye sample seems to have the potential candidate for use in various photonics and optoelectronics applications.

Linear and nonlinear optical properties of human hemoglobin

In this study, we investigated the possibility of interactions between the solvent molecules with the Heme group in the human hemoglobin. The results of this study answer a key question: whether the interactions of the Heme unit with its surroundings are interdependent or independent of the protein units of human hemoglobin. Contributions of the intermolecular interactions were determined by exploiting the solvatochromism spectroscopic data by Kamlet-Taft (KAT) polarity functions. Solvent polarity effects on the nonlinear properties of the Heme's groups in the human hemoglobin (Hb) were investigated via the Z-scan method. The experimental results obtained with spectroscopic and nonlinear optical parameters (absorption coefficient and refractive index) show that the mechanism of solvation and the interactions of Heme are controlled by suitable configuration of the protein units of hemoglobin. In other words, interactions of the Heme with α- and β-globins are an effective factor in controlling the optical behavior of Heme.

Solvent polarity sensitive characteristics of various tautomers of azo compounds: Linear and nonlinear optical properties

Solvents as complex environments can induce considerable effects on the physical, chemical and biological properties of solute molecules. In this work, solvent polarity sensitive characteristics of two tautomers of different azo compounds were studied by using of spectroscopic and Z-scan techniques. In this case, nature and various molecular interactions contribution on the spectral behaviors of azo and hydrazone forms of selected samples were investigated by Kamlet-Abboud-Taft and Catalan models. Moreover, the obtained results of Z-scan indicate that self-defocusing, saturable and reverse saturable absorption features of azo dyes depend highly on substituents and molecular environment polarity characteristic. In this case, media polarity properties have the same effects on the third order nonlinear absorption coefficient and nonlinear refractive index values. Therefore, by measuring one of the third order nonlinear optical coefficients, it is possible to predict solvent polarity effects on the other nonlinear optical coefficient. The calculated dipole moments with high values in the molecular excited state also reveal the probability of molecular charge transfer characteristics. In this case, by excitation process, sample I indicate high dipole moment values in comparison to other samples. Therefore, the results can give useful information about the application of selected samples for designing various optical devices.

Solvent Dependent Linear and Nonlinear Optical Characteristics of Acid Blue 3 Dye

The polar solvents dependent linear and third-order nonlinear optical (NLO) characteristics of acid blue 3 (AB 3) dye has been reported in this paper. A low power continuous wave (CW) diode laser working at 635 nm wavelength was used to perform the Z-scan experiments in the present study. AB 3 dye was dissolved with different polar solvents of 1-propanol, ethanol, dimethyl sulfonate (DMSO) and water at a concentration of 0.01 mM. The nonlinear index of refraction (n₂) of AB 3 dye was ascribed to self-defocusing effect, and nonlinear coefficient of absorption (β) signifies the behaviors of saturable and reverse saturable absorption. The real and imaginary components of the third-order NLO susceptibility of AB 3 dye in the present polar solvents have been measured to be of the order of 10^─6 esu. The influence of polar solvents on third-order NLO susceptibility of the dye sample studied has been discussed. The second-order hyperpolarizability (γ) of AB 3 dye has also been studied and estimated to be of the order of 10^─30 esu. The experimental results suggest that AB 3 dye may be a promising candidate for applications in nonlinear optics.