D.V. Petrov

First hyperpolarizability of CdS nanoparticles studied by hyper-Rayleigh scattering

The first hyperpolarizability of nanocrystalline CdS particles (mean diameters of 2.0, 5.6 and 9.1 nm) was measured by the hyper-Rayleigh scattering technique. The results show that the first hyperpolarizability per CdS pair increases with decreasing particle size. This is ascribed to quantum confinement effects on the oscillator strengths. These effects lead to an enhancement by one order of magnitude in the first hyperpolarizability of 2 nm CdS particles, in comparison with bulk CdS.

Reflection of a Gaussian beam from a saturable absorber

The modification of a Gaussian beam profile caused by the electronic contribution to the surface nonlinear absorption of a semiconductor doped glass was measured. The reflection Z-scan and transmission Z-scan techniques used allow to observe differences between the bulk and the surface nonlinear properties.

Nonlinear-optical properties of a poly(vinyl alcohol)- polyaniline interpenetrating polymer network

The nonlinear-optical properties of a semi-interpenetrating polymer network of poly(vinyl alcohol) glutaralde-hyde-polyaniline were studied. Large (>/=10(-12) cm(2)/W) and fast (<50 ps) refractive optical nonlinearites were observed. The potential of this novel material for photonic applications is evaluated.

Time‐resolved picosecond optical nonlinearity and all‐optical Kerr gate in poly (3‐hexadecylthiophene)

A time‐resolved anisotropic configuration exploiting the Z‐scan technique in a one color pump‐and‐probe arrangement was implemented to measure the time response and the value of the nondiagonal component of the third‐order nonlinear susceptibility of a chloroform solution of poly (3‐hexadecylthiophene). In addition, an all‐optical Kerr gate with picosecond response using the polymeric solution was implemented.

Saturation effects in the nonlinear-optical susceptibility of poly(3-hexadecylthiophene)

We performed Z-scan measurements to investigate the optical nonlinearity of poly(3-hexadecylthiophene) in a chloroform solution. Values for the real and the imaginary parts of the nonlinear susceptibility were obtained for solutions with various polymer concentrations. The nonlinear-optical properties were studied as a function of polymer concentration and light intensity from which saturation of nonlinear refraction and saturated absorption were observed. The saturation intensity was determined, and the corresponding values are presented for all concentrations studied. Time-resolved measurements of the nondiagonal part of nonlinear susceptibility are also presented.

Semiempirical calculations of aniline oligomers hyperpolarisabilities

Theoretical study of the hyperpolarisabilities β and γ of aniline oligomers is presented. The results obtained for β at the AM1/TDHF level are promising for the emeraldine form, indicating a potential use as a second-order nonlinear optical material. The calculations of static cubic hyperpolarisability of trimers agree with the experimentally observed trends for polyaniline.

Novel fabrication process of planar waveguides in rare‐earth doped fluoroindate glasses

We report the successful fabrication of planar waveguides in rare‐earth doped fluoroindate glass substrates. A new procedure for waveguide fabrication using a thermally evaporated AgF nonmetallic film was developed. The refractive index changes of more than 0.03, associated to low propagation losses achieved, open new perspectives and show the potentiality of using this glass family toward further developments in fabrication and design of integrated optical devices for optical communication wavelengths.

Nonlinear phase shift by cascaded quasi-phase-matched second harmonic generation

Abstract A phase shift for the input beam induced by cascaded second order nonlinear processes in structures with periodical modulation of linear and nonlinear susceptibilities is considered. Numerical examples are tabulated for LiNbO3/H+ : LiNbO3, GaAs/Ga0.8Al0.2As, and GaP/AlP periodical structures.

First hyperpolarizability of the molecular excited states: Calculations for p-nitroaniline and comparison with experiments

We calculated the first hyperpolarizability of the molecules with some fraction of both ground and excited state populations. We used a numerical procedure employed widely known software. The comparison with experimental data for para-nitroaniline molecule obtained by the Hyper-Rayleigh technique is done.

Hyper-Rayleigh scattering in p-nitroaniline with excited states obtained by 355 nm optical pump

We report what we believe to be the first experimental demonstration of the dependence of hyper-Rayleigh scattering (HRS) (fundamental wavelength of 1064 nm) and, hence, the first hyperpolarizability in optically pumped p-nitroaniline (PNA) molecules on the energy of pump photons.