Anton I. Maydykovskiy

Two‐Photon Luminescence and Second‐Harmonic Generation in Organic Nonlinear Surface Comprised of Self‐Assembled Frustum Shaped Organic Microlasers

An ultrathin nonlinear optical (NLO) organic surface composed of numerous self-assembled frustum-shaped whispering-gallery-mode resonators displays both two-photon luminescence and second-harmonic-generation signals. A super-second-order increase of the NLO intensity with respect to pump power confirms the microlasing action and practical usefulness of the NLO organic surfaces.

Polarization effects in diffraction-induced laser pulse splitting in one-dimensional photonic crystals

The polarization effects in the diffraction-induced pulse splitting (DIPS) observed under the dynamical Bragg diffraction in the Laue geometry in linear one-dimensional photonic crystals (PCs) are studied theoretically and experimentally. It is demonstrated that the characteristic length of the laser pulse path in a PC, or splitting length, used to describe the temporal pulse splitting, as well as the number of the outgoing femtosecond pulses, are influenced significantly by the polarization of the incident laser pulse. We have observed that the characteristic splitting time in porous quartz PCs for the s-polarized probe pulse is approximately 1.5 times smaller as compared with that measured for the p-polarized radiation. These results are supported by the theoretical description and ensure that the polarization sensitivity of the DIPS effect is due to a large lattice-induced dispersion of the PC. It is also shown that the number of output pulses can be varied from two up to four in both transmission and diffraction directions depending on the polarization of incident femtosecond pulses.

Optical study of polymer infiltration into porous Si-based structures

This work describes the infiltration of a polymeric solution into porous Si structures towards the fabrication of tunable photonic crystals (PC) and microcavities for photonics applications. The tunability is achieved by infiltrating the porous silicon based PCs by active organic materials, such as an emissive and nonlinear polymer called 2-methoxy-5-(2- ethylhexyloxy)-p-phenylenevinylene (namely MEH-PPV). This preliminary work shows the infiltration of this polymeric solution into PC based on macroporous Si structure as well as in microcavities based on multiple layers of microporous Si. The solidification of the polymer was obtained by the evaporation of the solvent. Various techniques of infiltration were studied to obtain an optimized filling of the pores. The infiltration was then characterized using photoluminescence measurements. Finally, we will report on the study of third harmonic generation (THG) in samples of porous silicon microcavity infiltrated with MEHPPV. The k-domain THG spectroscopy was applied and an increase of the THG intensity up to an order of magnitude was achieved for the filled microcavity.

Second harmonic generation study of internally-generated strain in bismuth-substituted iron garnet films

The present article highlights the lattice-imperfection and compositional origins of the nonlinear optical response in bismuth-substituted iron garnet films. In particular the roles of lattice mismatch strain and micro-strain on second harmonic generation in (Bi,Y)(3)(Fe,Ga)(5)O(12) films are elucidated based on experimental findings. It is found that lattice mismatch strain drives the second harmonic signal in (Bi,Y)(3)(Fe,Ga)(5)O(12) films, in agreement with theoretical predictions; however micro-strain was found not to correlate significantly with the second harmonic signal at the micro-strain levels present in these samples. The present study also elaborates on the influence of the films constitutive elements and finds the nonlinear response to increase with yttrium concentration.

Optical pendulum effect in one-dimensional diffraction-thick porous silicon based photonic crystals

We present the realization of the multiperiodic optical pendulum effect in 1D porous silicon photonic crystals (PhCs) under dynamical Bragg diffraction in the Laue scheme. The diffraction-thick PhC contained 360 spatial periods with a large variation of the refractive index of adjacent layers of 0.4. The experiments reveal switching of the light leaving the PhC between the two spatial directions, which correspond to Laue diffraction maxima, as the fundamental wavelength or polarization of the incident light is varied. A similar effect can be achieved when the temperature of the sample or the intensity of the additional laser beam illuminating the crystal are changed. We show that in our PhC structures, the spectral period of the pendulum effect is down to 5 nm, while the thermal period is about 10 °C.

Experimental demonstration of selective compression of femtosecond pulses in the Laue scheme of the dynamical Bragg diffraction in 1D photonic crystals

We present the experimental results of diffraction-induced temporal splitting of chirped femtosecond optical pulses under the dynamical Bragg diffraction in the Laue geometry. For the experiments we made a transparent, high quality porous-quartz based 1D photonic crystal composed of 500 layers. We demonstrate that a selective compression of pulses is observed in this case, that is only one pulse from the pair is compressed, while the second one is broadened. This selective compression effect is determined by the sign and the value of the chirp parameter of the input pulse, in agreement with the theoretical description.

Optical Second Harmonic Generation in Semiconductor Nanostructures

Optical second harmonic generation (SHG) studies of semiconductor nanostructures are reviewed. The second-order response data both predicted and observed on pure and oxidised silicon surfaces, planar Si(001)/SiO2 heterostructures, and the results related to the direct-current-and strain-induced effects in SHG from the silicon surfaces as well are discussed. Remarkable progress in understanding the unique capabilities of nonlinear optical second harmonic generation spectroscopy as an advanced tool for nanostructures diagnostics is demonstrated.

Enhancement of Nonlinear Optical Effects in Porous Composite Plasmonic Structures

A method for formation of bulk plasmonic structures based on porous quartz with silver nanoparticles in pores has been proposed and implemented. The spectroscopy of their optical and nonlinear optical properties has been performed by methods of second harmonic generation and two-photon absorption. A significant increase in the nonlinear absorption coefficient has been detected in the plasmon resonance region. The enhancement of the second optical harmonic has been observed with the shift by tens of nanometers from the plasmon resonance position toward the long-wavelength region.

Phase-matched second harmonic generation in one-dimensional photonic crystals in the Laue geometry

We experimentally observe phase-matched second harmonic generation under Bragg diffraction in the Laue geometry in one-dimensional porous silica based photonic crystals infiltrated by a ferroelectric salt.

New type of nanocomposite material for SERS

We experimentally observe effects of second harmonic generation, nonlinear absorbtion in porous quartz with metallic nanoparticles in order to find a possibility to make a new device for SERS-experiments.