International Journal of Optics and Photonics
Year:2007 | Volume:1 | Issue:1|Papers Count:7

Layer-by-layer (LBL) electrostatic assembly of poly-electrolytes is proving to be an increasingly rich and versatile technique for the formation of multilayered thin film with a wide range of electrical, magnetic, and optical properties. In the present work we synthesized a new nonlinear optical (NLO) maleic acid copolymer containing Disperse Red 1 moieties, built-up multilayer assemblies by alternate adsorption of poly (allylamine hydrochloride) (PAB) and maleic copolymer derivative, and carried out an investigation on their second harmonic generation (SHG) properties. The resulting multilayer assemblies exhibit SHG which arises from the non-centrosymmetric alignment of the chromophore in the copolymer. The SHG signal increases with the number of chromospheres-containing polymer layers, up to 5 layers. Further assembly reduces the signal.

Our recent advances in solid-state optoelectronic materials and devices will be reviewed. In the area of glass optics, fabrication of novel microstructured and multi-core fibers and their use in realizing single mode lasers will be summarized. In organic and plastic optics, photo refractive polymers for 3D display applications and nonlinear optical polymers for high speed modulators in RF photonic and remote antenna applications will be discussed. Our progress in medical optics including adaptive eyewear and imaging will also be described.

In this paper we present an in-depth review on the trends and the directions taken by the researchers worldwide in Optical Code Division Multiple Access (OCDMA) systems. We highlight those trends and features that are believed to be essential to the successful introduction of various OCDMA techniques in communication. Systems and data networks in near future. In particular we begin by giving a comprehensive review on the constructions of optical orthogonal codes (OOC). In our system study we first focus and discuss on various OCDMA techniques such as 1-D, 2-D and spectrally-encoded ultra short light pulse CDMA, and discuss their pros and cons. A comprehensive discussion takes place on all important aspects of each OCDMA technique. In particular, we elaborate on enabling technologies that are needed prior to full scale consideration of OCDMA in communication systems. We extend our discussion to various data networks, including fiber-based and wireless to indicate the directions and the applications that OCDMA systems are considered for. It is believed that OCDMA once fully developed and matured will be an inseparable part of advanced optical communication systems and networks due to its various desirable features and functionalities, in not so distant future.

The distribution function of the electrons produced in the interaction between an intense electromagnetic wave and a neutral gas is derived and is shown to be nonequilibrium and anisotropic. By assuming that the time scale of gas ionization is much greater than the field period, it is shown that the electron distribution function formed in microwave and optical discharges has sharp anisotropy affecting the discharge plasma. The anisotropy stimulated by the inequality of average longitudinal and transverse energy of electrons is investigated. Furthermore, the parametric instability stimulated by scattering of incident wave on the density oscillation of plasma under the positive slope of EDF with respect to velocity is studied.

CSs have been theoretically predicted and recently experimentally demonstrated in broad area, vertical cavity driven semiconductor lasers (VCSELs) slightly below the lasing threshold. Above threshold, the simple adiabatic elimination of the polarization variable is not correct, leading to oscillatory instabilities with a spuriously high critical wave-number. To achieve real insight on the complete dynamical problem, we study here the complete system of equations and find regimes where a Hopf instability, typical of lasers above threshold, affects the lower intensity branch of the homogeneous steady state, while the higher intensity branch is unstable due to a Turing instability. Numerical results obtained by direct integration of the dynamical equations show that writable/erasable CSs are possible in this regimes, sitting on unstable background.

Solid-state Raman lasers are known as important sources at normally difficult to access wavelengths, and our recent studies have shown that they also form the basis of a class of wavelength selectable lasers. This paper summarizes our recent studies in wavelength selectable Raman lasers in the visible (532-650nm) and ultraviolet (266-321 nm).

In this paper, by considering a system consisting of a single two-level trapped ion interacting with a single-mode quantized radiation field inside a lossless cavity, the temporal evolution of the ionic and the cavity-field quantum statistical properties including photon-counting statistics, quantum fluctuations of the field quadratures and quantum fluctuations of the ionic dipole variables are investigated. It is found that in the Lamb-Dicke limit it is possible for the cavity-field to evolve into a non classical state (squeezed state or state with sub-Poissonian statistics) and this possibility is solely affected by the internal and external quantum dynamics of the ion. Also it is found that the dipole squeezing may occur in the dynamics of the trapped ion which sensitively depends on quantum statistics of the cavity-field.