Optical nonlinearity of metal complexes of p-nitrophenolate (M=Li, Na and K) in ethanol is studied by using a continuous wave (cw) diode pumped Nd:YAG laser (532 nm, 50 mW). The predominant mechanism of observed nonlinearity is thermal in origin. The nonlinear refractive index and the nonlinear absorption coefficient of the samples were found to be in the order of 10-8 cm2/W and 10-3 cm/W respectively. Magnitude of third-order optical parameters varies according to the choice of alkali metal chosen for metal complex formation of p-nitrophenolate. The third-order nonlinear susceptibility was found to be in the order of 10-6 esu. The observed saturable absorption and the self-defocusing effect were used to demonstrate the optical limiting action at 532 nm by using the same cw laser beam. © 2015 Elsevier Ltd. All rights reserved.

Vinitha G

Physics

School of Advanced Sciences

Chennai Campus

Thangaraj M

Sabari Girisun T.C

Anandan P

Ravi G.

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Optics & Laser Technology

Metal-semi organic NLO single crystal of Cadmium (II) dibromide L - Proline monohydrate (CBLPM) has been synthesized and the crystal was grown from solution by room temperature slow evaporation method. The crystal structure and cell parameters were refined by Rietveld refinement technique and confirmed that the metal-semi organic samples are in the orthorhombic system with space group P212121. The crystal structure of CBLPM is stabilized by intermolecular N–H…O, N–H….Br, O–H….O and O–H….Br hydrogen bonds. The water molecules serve as donors for the weak O–H⋯O and O–H⋯Br hydrogen bonds which link adjacent chains forming a three-dimensional structure. A Hirshfeld surface analysis suggests that the most significant contribution to the crystal packing is by H⋯Br contacts (26.2%). The complete vibrational features and electronic absorption spectra of the title compound were analyzed by FT-IR, FT-Raman and UV–visible spectra combined with density functional theory and time-dependent density functional computations. The second-order hyperpolarizability value of the molecule was also calculated at density functional theory method. The third-order nonlinear optical properties of the crystal were studied by Z-scan techniques using CW laser with wavelength 532 nm. The open aperture result exhibits the saturation absorption, which indicates that this material has potential candidate for optical limiting applications. © 2019 Elsevier B.V.

Journal of Molecular Structure

Synthesis, physicochemical properties and third-order optical nonlinearities of cadmium (II) dibromide l - Proline monohydrate for optical limiting application

We report the growth process and linear and nonlinear optical characterization of high quality improvised semiorganic 2A5NPDP single crystal using the modified SR method for the first time. The major difficulties for the growth of 2A5NPDP single crystal have been resolved with the aid of a temperature lowering method. After optimization of the growth conditions, a transparent 2A5NPDP single crystal was harvested with a size of 85 mm length and 10 mm diameter over a period of 60 days. The growth rate of the modified SR method grown crystal was found to be 10 times higher than that of the conventional slow evaporation solution technique (SEST) grown crystal. The unit cell parameters of the grown crystal were ascertained by the single crystal X-ray diffraction (SXRD) and powder X-ray diffraction (PXRD) techniques. The high crystalline perfection of the crystal was ascertained by using a high-resolution X-ray diffraction (HRXRD) technique. The presence of multifarious functional groups of the 2A5NPDP crystal were confirmed by Fourier transform infrared (FT-IR) and Fourier transform Raman (FT-Raman) spectral analyses. The thermal property was assessed by the thermogravimetric (TG) and differential thermal analysis (DTA). It shows that the grown crystal withstands temperature up to 175 °C. UV-vis-NIR analysis was used to measure the linear optical property while third-order nonlinear optical properties were ascertained using Z-scan and optical limiting (OL) techniques. The optical limiting threshold of conventional method grown crystal is 5.7 mW/cm2, whereas the modified SR method grown crystal is 4.7 mW/cm2. Low value of limiting threshold indicates that the grown crystal has minimum defects. Finally, 800 nm wavelength of 140 fs at 80 MHz repetition rate obtained from a Ti:sapphire oscillator was used for the terahertz (THz) generation between 0.1 and 2.1 THz range. The efficiency of the generated THz signal was measured using another 800 nm wavelength of 40 fs, at 1 kHz repetition rate obtained from a Ti:sapphire amplifier. The generated THz signal is separated out from unconverted 800 nm using Teflon filters, and power is measured using a pyrometer. The maximum conversion efficiency of generated THz signal is on the order of 0.63 × 10-5%. Copyright © 2019 American Chemical Society.

Crystal Growth & Design

Evaluation of Linear and Nonlinear Optical Properties of D−π–A Type 2-Amino-5-Nitropyridinium Dihydrogen Phosphate (2A5NPDP) Single Crystal Grown by the Modified Sankaranarayanan–Ramasamy (SR) Method for Terahertz Generation

Single crystals of ammonium tetroxalate dihydrate doped with p-nitrophenol (PNP doped ATOXAL) were grown using the slow evaporation solution growth technique. The harvested crystals possessed the P1¯ space group and occupied the triclinic crystal system. From UV–vis-NIR spectrum the optical parameters like optical band gap (Eg), refractive index (n), electric susceptibility (χc) and real and imaginary parts of the dielectric constant were found to be 3.276 eV, 1.58, 0.199, 2.498 and 0.93 × 10−5 respectively at the lower cutoff wavelength. The refractive index value calculated using Abbe's refractometer was 1.581. The crystal exhibited negative photoconductivity. The photoluminescent emission spectrum was recorded and studied. The mechanical properties have been studied using Vicker's microhardness tester and the material belongs to the soft category. The thermal property of the crystal was analysed from the TGA/DTG/DSC curves. The dielectric studies carried out for varied frequencies and temperatures reveal that the material exhibits non-Debye β relaxation. Z-scan studies show that the grown crystal has negative nonlinearity and saturation absorption. © 2018 Elsevier Ltd

Effect of P-nitrophenol as dopant in ammonium tetroxalate dihydrate – Spectral, optical, thermal and dielectric analyses

A new third order nonlinear optical single crystal of Morpholin-4-ium hydrogen tartrate has been grown by the slow evaporation method. The lattice parameters and crystalline purity of this orthorhombic crystal were measured by single crystal X-ray diffraction and powder X-diffraction technique respectively. The optimized geometry shows that the morpholinium ring exist in a chair form where tartrate anions are linked via N–H⋯O hydrogen bonds, forming chains. These chains are linked via N–H⋯O and O–H⋯O hydrogen bonds, involving the morpholinium cation. The vibrational spectral investigation predicts that the red shifting of O–H and N–H stretching wavenumbers are due to O–H⋯O and N–H⋯O intermolecular interactions, respectively which are also evident form NBO analysis. The photoluminescence spectrum shows luminescence at the blue region with an appreciable lifetime leading to applications in blue OLEDs. Third order nonlinear optical properties like self-defocusing, saturable absorption and optical limiting at 532 nm are identified by Z-scan analysis. The laser damage threshold (LDT) energy have been measured by using Nd:YAG laser of wavelength 532 nm. The field dependent nature of first and second order hyperpolarizabilities and luminescence properties suggest that MHT crystal is a potential candidate for OLED and nonlinear optical applications. © 2019 Elsevier Ltd

Growth of Morpholin-4-ium hydrogen tartrate single crystal for optical limiting application

Proton transfer complex of Picolinium Tartrate Monohydrate (PTM) was synthesized and structure was confirmed by single crystal X-ray diffraction technique and 1 H &amp; 13 C NMR analysis. The molecular structural investigations by Hirshfeld surface, NBO and AIM analyses reveals that the picolinium cation and tartrate anion are interconnected through water molecule via strong N + -H … .O − and O + -H…O − hydrogen bonds. The harmonic wavenumber is computed with DFT/B3LYP/6–31++G(d,p) method and compared to the experimental FT-IR and FT-Raman with the help of Normal Coordinate Analysis (NCA) following scaled quantum mechanical force field methodology results the red shifting of N–H and O–H stretching vibrations due to the proton transfer. The solid state and solvent assisted photoluminescence spectrum shows that luminescence is at the blue region with appreciable lifetime. Third order nonlinear optical properties like self-defocusing, saturable absorption and optical limiting at 532 nm are identified by Z-scan analysis. The field dependent nature of first and second order hyperpolarizabilities and luminescence properties suggest that PTM crystal is a potential candidate for non-linear optical and OLED applications. The correlation between proton transfer, hole-electron transport and charge transfer interaction explores in this study. © 2019 Elsevier Ltd

Dyes and Pigments

Proton-induced intermolecular charge transfer in Picolinium Tartrate Monohydrate crystal for OLED and nonlinear optical applications: A combined experimental and computational study

Materials Chemistry and Physics

χ(3) measurement and optical limiting properties of metal complexes of thiourea using Z-scan

Crystal Research and Technology

Linear and nonlinear optical properties of tris thiourea zinc sulphate single crystals

Synthetic Metals

Third order nonlinear optical properties and two photon absorption in newly synthesized phenyl sydnone doped polymer

Physical Review B

Second-order optical effects in organometallic nanocomposites induced by an acoustic field

The Journal of Physical Chemistry B

χ(2)Grating in Ru Derivative Chromophores Incorporated within the PMMA Polymer Matrices

Third order nonlinear optical properties and optical limiting behavior of alkali metal complexes of p-nitrophenol

Journal	Data powered by TypesetOptics & Laser Technology
Publisher	Data powered by TypesetElsevier BV
ISSN	0030-3992
Open Access	No