The control of luminous radiation has extremely important implications for modern and future technologies as well as in medicine. In this Review, we detail chemical structures and their relevant photophysical features for various groups of materials, including organic dyes such as metalloporphyrins and metallophthalocyanines (and derivatives), other common organic materials, mixed metal complexes and clusters, fullerenes, dendrimeric nanocomposites, polymeric materials (organic and/or inorganic), inorganic semiconductors, and other nanoscopic materials, utilized or potentially useful for the realization of devices able to filter in a smart way an external radiation. The concept of smart is referred to the characteristic of those materials that are capable to filter the radiation in a dynamic way without the need of an ancillary system for the activation of the required transmission change. In particular, this Review gives emphasis to the nonlinear optical properties of photoactive materials for the functi...

Nonlinear Optical Materials for the Smart Filtering of Optical Radiation.

In this work, the green synthesis of highly fluorescent carbon quantum dots (CQDs) with an efficient quantum yield of 17.98% using sugarcane bagasse pulp as the precursor was conducted by a hydrothermal technique. The high-resolution transmission electron microscopy analysis revealed that the CQDs were competently monodispersed with the particle size ranging between 0.75 and 2.75 nm. The structural properties of CQDs were investigated using X-ray diffraction, Fourier transform infrared, and X-ray photoelectron spectroscopy analyses. The UV-visible spectrum showed two absorption peaks due to the aromatic C=C transitions of π-π* and C=O transitions of n-π*. The fluorescence spectrum of CQDs displayed a strong blue emission. However, the first-ever of its kind, sugarcane industrial solid waste carbon quantum dots caused significant orders to obey the enhancement of the third-order nonlinearity (χ(3)) when compared with other carbon dots (CDs). The calculated nonlinear optical (NLO) parameters such as n 2, β, and χ(3) were 1.012 × 10-8 cm2/W, 2.513 × 10-4, and 3.939 × 10-7 esu, respectively. The figures of merit were evaluated to be W = 6.6661 and T = 0.0132, which greatly fulfilled the optical switching conditions. Besides, the antibacterial activities of CQDs were screened against aquatic Gram-positive (Benthesicymus cereus and Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa, Vibrio cholerae, and Escherichia coli) microbial organisms. Our findings, however, indicate that synergistic sugarcane industrial waste CQDs are promising materials for the functioning of NLO devices, bioimaging, and pharmaceutical applications.

Biocompatible Carbon Quantum Dots Derived from Sugarcane Industrial Wastes for Effective Nonlinear Optical Behavior and Antimicrobial Activity Applications.

Progress in the enhancement of electro-optic coefficients and orientation stability for organic second-order nonlinear optical materials

Effect of l-threonine on growth and properties of ammonium dihydrogen phosphate crystal

Synthesis, growth, structural and HOMO and LUMO, MEP analysis of a new stilbazolium derivative crystal: A enhanced third-order NLO properties with a high laser-induced damage threshold for NLO applications

A new organic stilbazolium derivative crystal 2-[2-(3-hydroxy-4-methoxy-phenyl)-vinyl]-1-methyl-pyridinium naphthalene-2-sulfonate dehydrate (C25H23NO5S·2H2O) (VSNS) was synthesized successfully. Single crystals were grown in a mixed solvent of methanol–acetonitrile (1 : 1) using a slow evaporation method at room temperature. Solubility of the synthesized VSNS material was experimentally determined for various temperatures using a methanol–acetonitrile mixed solvent. A single crystal X-ray diffraction study confirmed the crystal structure and morphology of VSNS. The crystalline nature of the title material was analyzed by powder X-ray diffraction analysis, and the presence of expected functional groups and the molecular structure of VSNS was identified by FT-IR and 1H NMR spectroscopic studies. Optical absorption was recorded using UV-Vis-NIR spectral analysis, and linear optical constants such as the absorption coefficient, band gap, extinction coefficient, refractive index and reflectance were calculated. The luminescence property of the crystal grown showed green emission radiation. The thermal stability of the crystal was analyzed by TG–DTA studies, and the hardness, Meyer index, yield strength, and elastic stiffness constant were estimated using a Vickers microhardness tester. Layer growth pattern was observed in chemical etching studies using a Carl Zeiss optical microscope at 50× magnification. Laser damage threshold energy was measured using an Nd:YAG laser (1064 nm). Variation of the dielectric response of the grown crystal was studied at room temperature. The third-order nonlinear optical property of VSNS was investigated in detail using a Z-scan technique with He–Ne laser at 632.8 nm. The second-order molecular hyperpolarizability γ of the crystal grown was 7.986 × 10−34 esu. This encouraging result of the Z-scan studies suggests that the VSNS crystal is a candidate material for photonics devices, optical switches, and optical power limiting applications.

Investigation of synthesis, crystal structure and third-order NLO properties of a new stilbazolium derivative crystal: a promising material for nonlinear optical devices

P.G. Aravindan

Papers

Investigation of synthesis, crystal structure and third-order NLO properties of a new stilbazolium derivative crystal: a promising material for nonlinear optical devices

Synthesis, growth, structural and HOMO and LUMO, MEP analysis of a new stilbazolium derivative crystal: A enhanced third-order NLO properties with a high laser-induced damage threshold for NLO applications

Growth and characterization of a new organic single crystal: 1-(4-Nitrophenyl) pyrrolidine (4NPY).