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Green–blue plasmonic random laser is attained by two-dimensional plexcitonic structure. The main gain plexcitonic media contained two-dimensional periodic arrays of gold nanowires which is covered by dye layer. Due to the change in the strength of exciton and plasmon coupling in these plexcitonic gain structures, different close loop, and thus random lasing must be takes place. For this purpose, we fabricate six samples with different plexcitonic power and pumped fabricated two-dimensional nanostructures by green nanosecond pulsed laser. Our results show efficient coherent random lasing due to the plexcitonic nanostructure in the blue, because two-photon absorption and also green part of the visible spectral region considering its applicability in the design and fabrication of compact and miniaturized random laser sources. [ABSTRACT FROM AUTHOR]

The optical properties, linear and nonlinear, for Leishman stain are studied in ethanol and chloroform over a wide spectral region. The stain consists of two components: Methylene blue (MB) and Eosin (E). The low intensity optical measurements, linear regime, show the absorption and emission characteristics of the E and the MB components in ethanol and only the MB component in chloroform. Under the influence of optical intensity less than 15 MW/m2, the stain shows nonlinear absorption characteristics at excitation wavelengths 532 nm and 650 nm only. The nonlinear absorption coefficients of the solutions are in 1–12.4 × 1 0 − 3 cm/W range in both solvents. Leishman stain solutions in ethanol and chloroform have a strong thermal nonlinearity with a negative index of refraction over the entire visible region. The value of the nonlinear refractive index ( n 2 ) of Leishman stain in both solvents increases as the wavelength of the excitation radiation increases. The value of n 2 of the solutions is in the range of about 2–46 × 1 0 − 7 cm2/W. As an example of the optoelectronic applications, the stain shows excellent properties of an energy spreading optical limiter. [ABSTRACT FROM AUTHOR]

The features of silver nanowire random laser (different sizes and concentrations)-based random lasers with a fixed concentration of laser dye rhodamine B pumped by a nanosecond pulsed laser were indicated. It was shown that the sizes and concentrations of scattering centers greatly affect the optical amplification mechanism, thresholds, narrowing the emission intensity and then the transition from the incoherent to a coherent type of random laser. The emergence of spikes and the increase in their number are also discussed under the influence of the size and concentration of silver (Ag) nanowires. The gain narrowing and the enhancement factor were calculated to reinforce obtained results. [ABSTRACT FROM AUTHOR]

This work is focused on the characterization of the opto-heating generation in thermo-piezo-plasmonic solutions of gold-PbZrTiO3 (PZT) core/shell nanoparticles. Core/shell nanoparticles have been prepared by the laser ablation in liquid method. Linear and nonlinear optical properties of proposed nanoparticles were studied by optical spectroscopy and the Z-scan technique under external voltage to investigate the piezo-photonic effect. Furthermore, the linear optical properties of these nanostructures were calculated vie dipole approximation method with different core size and different shell thickness of samples immersed in water and poly-vinyl-pyrrolidone. In addition, thermo-plasmonic effects of samples are investigated theoretically and experimentally by the finite element method of COMSOL multiphysics V5.4 and infrared camera under laser irradiation and external electric field. The results revealed a clear tunable and adjustable linear and nonlinear behavior and thermo-piezo-plasmonic properties under external effects. The temperature elevation is ranging of ∆T = 3.7–14.1 °C under different external effects. Accordingly, these results encourage to uses proposed samples for the cancer treatment and the different biomedical applications. [ABSTRACT FROM AUTHOR]