A. Chabanov - Academia.edu (original) (raw)

Papers by A. Chabanov

Optica

The application of parity–time (PT) symmetry in optics, especially PT-symmetry breaking, has attr... more The application of parity–time (PT) symmetry in optics, especially PT-symmetry breaking, has attracted considerable attention as an approach to controlling light propagation. Here, we report optical limiting by two coupled optical cavities with a PT-symmetric spectrum of reflectionless modes. The optical limiting is related to broken PT symmetry due to light-induced changes in one of the cavities. Our experimental implementation involves a three-mirror resonator of alternating layers of ZnS and cryolite with a PT-symmetric spectral degeneracy of two reflectionless modes. The passive optical limiting is demonstrated by measurements of single 532 nm 6 ns laser pulses and thermo-optical simulations. At fluences below 10mJ/cm2, the multilayer exhibits a flattop passband at 532 nm. At higher fluences, laser heating combined with the thermo-optic effect in ZnS leads to cavity detuning and PT-symmetry breaking of the reflectionless modes. As a result, the entire multilayer structure quickl...

Advances in Optical Imaging and Photon Migration

We report measurements of the intensity and phase distributions of microwave radiation transmitte... more We report measurements of the intensity and phase distributions of microwave radiation transmitted through random media. Changes in the statistics of the field as propagation varies from being predominantly ballistic to diffusive are studied.

EPL (Europhysics Letters), 2019

2010 20th International Conference on Electronics Communications and Computers (CONIELECOMP), 2010

In order to explore the functionalization of wearable fabrics for power generation, barium titana... more In order to explore the functionalization of wearable fabrics for power generation, barium titanate (BTO) was deposited on nickel tape and on carbon fiber fabric employing pulsed laser deposition (PLD) methods under conditions normally not considered ideal to produce optimum ferroelectric properties, namely, at temperatures as low as 100 °C and under various oxygen partial pressures. The remnant charge polarization and film resistance properties were evaluated to determine the effect of the aforementioned deposition conditions. The C-V characterization indicates that the BTO films still retained ferroelectric properties in films produced at temperature as low as 200 °C, below which, the behavior was only paraelectric.

Conference on Lasers and Electro-Optics/International Quantum Electronics Conference and Photonic Applications Systems Technologies, 2004

ABSTRACT We observe weak and strong localization in the time domain as the nonexponential decay o... more ABSTRACT We observe weak and strong localization in the time domain as the nonexponential decay of the tail of the time-of-flight distribution and as increasing intensity correlation in time for multiply scattered microwave radiation

Methods and Applications of Analysis, 2004

Photonic Metamaterials: From Random to Periodic, 2007

Waves and Imaging through Complex Media, 2001

A statistical description of wave propagation in random media is necessary to characterize large ... more A statistical description of wave propagation in random media is necessary to characterize large fluctuations found in these samples. The nature of fluctuations is determined by the closeness to the localization transition. In the absence of inelastic processes, this can be specified, in many circumstances, by a single parameter — the ensemble average of the dimensionless conductance. As a result, the extent of localization can be determined by any of a wide variety of related statistical measurements. Among the quantities that most directly reflect key aspects of localization are the following: (i) the ensemble average of the dimensionless conductance, (ii) the degree of spatial correlation of intensity, (iii) the variances of the probability distribution of transmission quantities, such as the intensity, the total transmission, and the dimensionless conductance, and (iv) the ratio of the width to the spacing of modes of an open sample. We will emphasize the relationships between key statistical aspects of propagation in quasi-one-dimensional samples and the different impact of absorption upon these. We find that even in the presence of absorption, the extent of localization can be characterized by a single parameter — the variance of the total transmission normalized by its ensemble average. Measurements of fluctuations in intensity and total transmission of microwave radiation allow us to study photon localization in collections of dielectric spheres and in periodic metallic wire meshes containing metallic scatterers. We find in low-density collections of alumina spheres contained in a copper tube, at frequencies near the first Mie resonance, that the variance of normalized total transmission scales exponentially once it becomes greater than unity. When this parameter is large, transmission spectra are observed to be a series of narrow lines with widths that are smaller than the separation between peaks. These spectra have an extraordinarily wide intensity distribution and correspondingly large variance. These results demonstrate that the variance of normalized transmission serves as a powerful guide in the search for and characterization of photon localization.

Frontiers in Optics, 2003

2010 20th International Conference on Electronics Communications and Computers (CONIELECOMP), 2010

Zinc oxide thin films are becoming increasingly popular for their wide range of properties and th... more Zinc oxide thin films are becoming increasingly popular for their wide range of properties and the ability to deposit these films on organic substrates for applications such as biotemplating, OLEDs, or deposition on fabrics for functionalization purposes including power generation from the flexing and deformation of wearable textiles. However, since many fabrics and other organic substrates can not survive the typically high temperatures of thin film growth, it is important to characterize and understand the dependence of the properties of these films as a function of temperature deposition and subsequent thermal treatments. We report on the properties of zinc oxide thin films grown by Atomic Layer Deposition (ALD) and the dependence of surface roughness, film stress, surface energy and crystalline structure on deposition temperature.

The residual stress in a thin film can have an impact on the electrical and optical properties of... more The residual stress in a thin film can have an impact on the electrical and optical properties of the film. In addition, stress is an important consideration when incorporating the material into a microelectromechanical (MEMS) device as large unexpected stresses can cause such a device to fail. The residual stress in ZnO thin films prepared by atomic layer deposition was

Ferroelectric BaTiO3 thin films were integrated directly on metallic Ni tapes by using pulsed las... more Ferroelectric BaTiO3 thin films were integrated directly on metallic Ni tapes by using pulsed laser for energy harvesting applications. Microstructure studies from x-ray diffraction and electron microscopy indicate that the as-grown BaTiO3 thin films have pure BaTiO3 crystal phase which consists of the crystalline assemblage of nanopillars with average cross sections from 100 nm to 200 nm directly on the

Frontiers in Optics 2011/Laser Science XXVII, 2011

ABSTRACT