ISRN Optics http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2014 , Hindawi Publishing Corporation . All rights reserved. Designing an Ultra-Negative Dispersion Photonic Crystal Fiber with Square-Lattice Geometry Tue, 01 Apr 2014 08:45:44 +0000 http://www.hindawi.com/journals/isrn.optics/2014/545961/ We have theoretically investigated the dispersion characteristics of dual-core PCF, based on square-lattice geometry by varying different parameters. The fiber exhibits a very large negative dispersion because of rapid slope change of the refractive indices at the coupling wavelength between the inner core and outer core. The dependence of different geometrical parameters, namely, hole-to-hole spacing () and different air-hole diameter (), was investigated in detail. By proper adjustment of the available parameters, a high negative dispersion value of 47,500 ps/nm/km has been achieved around the wavelength of 1550 nm. Our proposed fiber will be an excellent device for dispersion compensation in long-haul data transmission as being thousand times more than the available DCFs. Partha Sona Maji and Partha Roy Chaudhuri Copyright © 2014 Partha Sona Maji and Partha Roy Chaudhuri. All rights reserved. Characterization of Silver Oxide Films Formed by Reactive RF Sputtering at Different Substrate Temperatures Tue, 18 Mar 2014 08:38:19 +0000 http://www.hindawi.com/journals/isrn.optics/2014/684317/ Silver oxide (A2O) films were deposited on glass and silicon substrates held at temperatures in the range 303–473 K by reactive RF magnetron sputtering of silver target. The films formed at room temperature were single phase Ag2O with polycrystalline in nature, while those deposited at 373 K were improved in the crystallinity. The films deposited at 423 K were mixed phase of Ag2O and Ag. Atomic force micrographs of the films formed at room temperature were of spherical shape grains with size of 85 nm, whereas those deposited at 473 K were with enhanced grain size of 215 nm with pyramidal shape. Electrical resistivity of the single phase films formed at room temperature was 5.2 × 10−3 Ωcm and that of mixed phase was 4.2 × 10−4 Ωcm. Optical band gap of single phase films increased from 2.05 to 2.13 eV with the increase of substrate temperature from 303 to 373 K, while in mixed phase films it was 1.92 eV. P. Narayana Reddy, M. Hari Prasad Reddy, J. F. Pierson, and S. Uthanna Copyright © 2014 P. Narayana Reddy et al. All rights reserved. Wavelength Dependent Haze of Transparent Glass-Particle Filled Poly(Methyl Methacrylate) Composites Wed, 12 Mar 2014 10:22:05 +0000 http://www.hindawi.com/journals/isrn.optics/2014/802369/ Glass particles as filler were incorporated in a poly(methyl methacrylate) matrix. The refractive indexes of both materials match at a wavelength of about 400 nm. The effect of particle volume fraction on the light transmittance and light scattering (haze) in dependence of the refractive index difference was studied. The curve shape of the haze in dependence of the wavelength is comparable to that of the refractive index difference, but the base line of the haze increases with the filling grade. This indicates that there are other scattering or absorbing mechanisms, like defects in the filler binding. Wolfgang Wildner and Dietmar Drummer Copyright © 2014 Wolfgang Wildner and Dietmar Drummer. All rights reserved. Nonclassical Effects of Light in Fifth Harmonic Generation up to First-Order Hamiltonian Interaction Sun, 09 Mar 2014 09:31:26 +0000 http://www.hindawi.com/journals/isrn.optics/2014/580262/ The nonclassical effects of light in the fifth harmonic generation are investigated by quantum mechanically up to the first-order Hamiltonian interaction. The coupled Heisenberg equations of motion involving real and imaginary parts of the quadrature operators are established. The occurrence of amplitude squeezing effects in both quadratures of the radiation field in the fundamental mode is investigated and found to be dependent on the selective phase values of the field amplitude. The photon statistics in the fundamental mode have also been investigated and found to be sub-Poissonian in nature. It is observed that there is no possibility to produce squeezed light in the harmonic mode up to first-order Hamiltonian interaction. Further, we have found that the normal squeezing in the harmonic mode directly depends upon the fifth power of the field amplitude of the initial pump field up to second-order Hamiltonian interaction. This gives a method of converting higher-order squeezing in the fundamental mode into normal squeezing in the harmonic mode and vice versa. The analytic expression of fifth-order squeezing of the fundamental mode in the fifth harmonic generation is established. Rajendra Pratap, D. K. Giri, and Ajay Prasad Copyright © 2014 Rajendra Pratap et al. All rights reserved. A Method for the Measurement of Photons Number and Squeezing Parameter in a Quantum Cavity Tue, 31 Dec 2013 10:33:09 +0000 http://www.hindawi.com/journals/isrn.optics/2013/271951/ Measurement of photons number in a quantum cavity is very difficult and the photons number is changed after each measurement. Recently, many efforts have been done for the nondemolition measurement methods. Haroche et al. succeed in recognizing existence or nonexistence of one photon in a quantum cavity. In this paper, we employ their experimental setup for a quantum nondemolition measurement and pump a coherent state in their quantum cavity. In this case, we could detect more photons in the quantum cavity by a measurement of a displaced Wigner function. It is also shown that the measurement of more than one photon is possible by the Haroche method by measuring just one point of displaced Wigner function. Furthermore, if the cavity field is filled by a superposition of two number states, the average number of photons within the cavity would be measurable. We show that their setup is also suitable to apply for the measurement of the squeezing parameter for the squeezed state of photons number in the quantum cavity successfully. Ghasem Naeimi, Siamak Khademi, and Ozra Heibati Copyright © 2013 Ghasem Naeimi et al. All rights reserved. Temperature Measurement Method Based on Riesz Transform Method Wed, 11 Dec 2013 13:24:55 +0000 http://www.hindawi.com/journals/isrn.optics/2013/967357/ A method to measure the temperature of a metal plate is presented using a Riesz transform method and the monogenic signal to extract the optical phase distribution from a fringe pattern from which one can get the unknown temperature. The performance of this method is evaluated by the RFSIM metric obtained from the 2nd-order Riesz transform. A phase distribution with a good accuracy is provided. Sara Zada, Salah Darfi, Vamara Dembele, Said Rachafi, and Abdelkarim Nassim Copyright © 2013 Sara Zada et al. All rights reserved. Admittance Loci Based Design of a Plasmonic Structure Using Ag-Au Bimetallic Alloy Film Tue, 10 Dec 2013 08:11:18 +0000 http://www.hindawi.com/journals/isrn.optics/2013/946832/ A theoretical study based on the use of admittance loci method in the design of surface plasmon resonance (SPR) based structure using Ag-Au bimetallic alloy film of different alloy fractions and nanoparticle sizes has been reported along with some interesting performance related simulated results at 633 nm wavelength. The sensitivity and other performance parameter issues of the structure based on the choice of correct alloy fraction and nanoparticle size of Ag-Au bimetallic alloy film have also been discussed giving due importance to the dynamic range of the designed structure. Kaushik Brahmachari and Mina Ray Copyright © 2013 Kaushik Brahmachari and Mina Ray. All rights reserved. Circular Photonic Crystal Fibers: Numerical Analysis of Chromatic Dispersion and Losses Wed, 13 Nov 2013 08:59:32 +0000 http://www.hindawi.com/journals/isrn.optics/2013/986924/ Detailed numerical analysis for dispersion properties and losses has been carried out for a new type of Photonic crystal fiber where the air-holes are arranged in a circular pattern with a silica matrix called as Circular Photonic Crystal Fiber (C-PCF). The dependence of different PCF geometrical parameters namely different circular spacings, air-hole diameter and numbers of air-hole rings are carried out in detail towards practical applications. Our numerical analysis establishes that total dispersion is strongly affected by the interplay between material dispersion and waveguide dispersion. For smaller air-filing fraction, adding extra air-hole rings does not change dispersion much whereas for higher air-filling fraction, the dispersion nature changes significantly. With proper adjustment of the parameters ultra-flattened dispersion could be achieved; though the application can be limited by higher losses. However, the ultra-flat dispersion fibers can be used for practical high power applications like supercontinuum generation (SCG) by reducing the loss at the pumping wavelength by increasing the no of air-hole rings. Broadband smooth SCG can also be achieved with low loss oscillating near-zero dispersion fiber with higher no of air-hole rings. The detail study shows that for realistic dispersion engineering we need to be careful for both loss and dispersion. Partha Sona Maji and Partha Roy Chaudhuri Copyright © 2013 Partha Sona Maji and Partha Roy Chaudhuri. All rights reserved. Numerical Analysis of Ridged-Circular Nanoaperture for Near-Field Optical Disk Tue, 29 Oct 2013 09:00:45 +0000 http://www.hindawi.com/journals/isrn.optics/2013/543960/ A ridged-circular nanoaperture is investigated through three-dimensional (finite-difference time-domain) FDTD method. The motion equations of free electrons are inserted to analyze a metallic material. The electromagnetic field distributions of optical near-field around the aperture are investigated. The phase change disk illuminated by a near-field optical light through a ridged-circular nanoaperture is also analyzed. The far-field scattering patterns from the phase change disk and the crosstalk characteristics between plural marks are studied. Toshiaki Kitamura Copyright © 2013 Toshiaki Kitamura. All rights reserved. A Modified Structure for All-Glass Photonic Bandgap Fibers: Dispersion Characteristics and Confinement Loss Analysis Sun, 22 Sep 2013 15:46:52 +0000 http://www.hindawi.com/journals/isrn.optics/2013/416537/ This paper investigates a modified structure for all-glass photonic bandgap fiber (AGPBF) having up-doped silica rods in the cladding region instead of air holes using plane wave expansion (PWE) and finite difference time domain (FDTD) methods. The proposed AGPBF structure exhibits tunable dispersion properties and improved confinement loss. It is observed that the confinement loss can be reduced simply by using a higher doping concentration in silica rods in the cladding. Also, it is possible to achieve flattened dispersion of the order of 1 ps/nm/km over a wide wavelength range. Sanjaykumar Gowre, Sudipta Mahapatra, and P. K. Sahu Copyright © 2013 Sanjaykumar Gowre et al. All rights reserved. Universal Dynamical Control of Open Quantum Systems Thu, 19 Sep 2013 08:50:25 +0000 http://www.hindawi.com/journals/isrn.optics/2013/783865/ Due to increasing demands on speed and security of data processing, along with requirements on measurement precision in fundamental research, quantum phenomena are expected to play an increasing role in future technologies. Special attention must hence be paid to omnipresent decoherence effects, which hamper quantumness. Their consequence is always a deviation of the quantum state evolution (error) with respect to the expected unitary evolution if these effects are absent. In operational tasks such as the preparation, transformation, transmission, and detection of quantum states, these effects are detrimental and must be suppressed by strategies known as dynamical decoupling, or the more general dynamical control by modulation developed by us. The underlying dynamics must be Zeno-like, yielding suppressed coupling to the bath. There are, however, tasks which cannot be implemented by unitary evolution, in particular those involving a change of the system’s state entropy. Such tasks necessitate efficient coupling to a bath for their implementation. Examples include the use of measurements to cool (purify) a system, to equilibrate it, or to harvest and convert energy from the environment. If the underlying dynamics is anti-Zeno like, enhancement of this coupling to the bath will occur and thereby facilitate the task, as discovered by us. A general task may also require state and energy transfer, or entanglement of noninteracting parties via shared modes of the bath which call for maximizing the shared (two-partite) couplings with the bath, but suppressing the single-partite couplings. For such tasks, a more subtle interplay of Zeno and anti-Zeno dynamics may be optimal. We have therefore constructed a general framework for optimizing the way a system interacts with its environment to achieve a desired task. This optimization consists in adjusting a given “score” that quantifies the success of the task, such as the targeted fidelity, purity, entropy, entanglement, or energy by dynamical modification of the system-bath coupling spectrum on demand. Gershon Kurizki Copyright © 2013 Gershon Kurizki. All rights reserved. Uncertainty Estimation due to Geometrical Imperfection and Wringing in Calibration of End Standards Wed, 18 Sep 2013 08:24:22 +0000 http://www.hindawi.com/journals/isrn.optics/2013/697176/ Uncertainty in gauge block measurement depends on three major areas, thermal effects, dimension metrology system that includes measurement strategy, and end standard surface perfection grades. In this paper, we focus precisely on estimating the uncertainty due to the geometrical imperfection of measuring surfaces and wringing gab in calibration of end standards grade 0. Optomechanical system equipped with Zygo measurement interferometer (ZMI-1000A) and AFM technique have been employed. A novel protocol of measurement covering the geometric form of end standard surfaces and wrung base platen was experimentally applied. Surface imperfection characteristics of commonly used 6.5 mm GB have been achieved by AFM in 2D and 3D to be applied in three sets of experiments. The results show that there are obvious mapping relations between the geometrical imperfection and wringing thickness of the end standards calibration. Moreover, the predicted uncertainties are clearly estimated within an acceptable range from 0.132 µm, 0.164 µm and 0.202 µm, respectively. Experimental and analytical results are also presented. Salah H. R. Ali and Ihab H. Naeim Copyright © 2013 Salah H. R. Ali and Ihab H. Naeim. All rights reserved. Relativistic Propagation of Linearly/Circularly Polarized Laser Radiation in Plasmas Mon, 02 Sep 2013 15:58:42 +0000 http://www.hindawi.com/journals/isrn.optics/2013/642617/ Paraxial theory of relativistic self-focusing of Gaussian laser beams in plasmas for arbitrary magnitude of intensity of the beam has been presented in this paper. The nonlinearity in the dielectric constant arises on account of relativistic variation of mass. An appropriate expression for the nonlinear dielectric constant has been used to study laser beam propagation for linearly/circularly polarized wave. The variation of beamwidth parameter with distance of propagation, self-trapping condition, and critical power has been evaluated. The saturating nature of nonlinearity yields two values of critical power of the beam ( and ) for self-focusing. When the beam diverges. When the beam first converges then diverges and so on. When the beam first diverges and then converges and so on. Numerical estimates are made for linearly/circularly polarized wave applicable for typical values of relativistic laser-plasma interaction process in underdense and overdense plasmas. Since the relativistic mechanism is instantaneous, this theory is applicable to understanding of self-focusing of laser pulses. Sonu Sen, Meenu Asthana Varshney, and Dinesh Varshney Copyright © 2013 Sonu Sen et al. All rights reserved. Perturbation Analysis with Approximate Integration for Propagation Mode in Two-Dimensional Two-Slab Waveguides Thu, 22 Aug 2013 13:49:28 +0000 http://www.hindawi.com/journals/isrn.optics/2013/108704/ On the basis of perturbation expansion from a gapless system, we calculate the propagation constant and propagation mode wave function in two-dimensional two-slab waveguides with a core gap small enough that there is only one propagation mode. We also perform calculations without the approximation for comparison. Our result shows that first-order perturbation contains the first-order Taylor expansion of (core gap)/(core width), and when the integration of the perturbation is suitably approximated, the result of the first-order perturbation is the same as that of the first-order Taylor expansion of (core gap)/(core width). Naofumi Kitsunezaki Copyright © 2013 Naofumi Kitsunezaki. All rights reserved. Thin Light Tube Formation by Tightly Focused Azimuthally Polarized Light Beams Mon, 19 Aug 2013 08:41:06 +0000 http://www.hindawi.com/journals/isrn.optics/2013/185495/ Theoretical and numerical analysis of the transmission function of the focusing system with high numerical aperture was conducted. The purpose of the study was to form a thin light tube in a focal area using the azimuthally polarized radiation. It was analytically shown that, due to destructive interference of two beams formed by two narrow rings, it is possible to overcome not only the full aperture diffraction limit but also the circular aperture limit. In this case, however, the intensity at the center of the focal plane is significantly reduced, which practically leads to the tube rupture. It was numerically shown that long thin one-piece tubes may be formed through the aperture apodization with diffractive axicon phase function or with complex transmission function of Laguerre-Gaussian or Airy-Gaussian beams. Svetlana N. Khonina and Andrey V. Ustinov Copyright © 2013 Svetlana N. Khonina and Andrey V. Ustinov. All rights reserved. The Field and Energy Distributions of the Fundamental Mode in the Solid-Core Photonic Crystal Fibers for Different Geometric Parameters Tue, 06 Aug 2013 08:17:51 +0000 http://www.hindawi.com/journals/isrn.optics/2013/567501/ For a solid core photonic crystal fiber with the triangular lattice, the field and energy distributions of fundamental mode are considered at 1.55 μm wavelength. The silica core is constituted by removing the 7 air holes. The cladding consists of the two-dimensional silica-air photonic crystal with the 4 rings of air holes. The field and energy distributions were investigated for three different values of . Here, d and represent the diameter of air holes and the pitch length, respectively. The simulations show that, for the fixed , the increase in ratio does not cause the considerable changes in the field and energy intensity distributions, but for the fixed , the increase in this ratio affects the intensity distributions reasonably. Halime Demir Inci and Sedat Ozsoy Copyright © 2013 Halime Demir Inci and Sedat Ozsoy. All rights reserved. Combined Experimental and Monte-Carlo Ray-Tracing Approach for Optimizing Light Extraction in LED COB Modules Wed, 24 Jul 2013 10:17:24 +0000 http://www.hindawi.com/journals/isrn.optics/2013/385345/ High-power light-emitting diodes (LEDs) for lighting applications require a high-efficient packaging to optimize their performances. Due to its high thermal dissipation potential, the chip-on-board (COB) technology is widely used for developing high-power lighting sources. In order to optimize the optical properties of such sources and to propose high optically efficient encapsulation geometry, ray-tracing simulations have been performed. The impact of the shape and volume of the silicone encapsulation on the light extraction and on the intensity distribution of the module was derived. Then, simulation results were correlated with experimental measurements on blue light-emitting COB sources. It is shown that a nearly hemispherical encapsulation with a minimal volume of 5 to 10 mm3 for a 1 mm2 LED die is the optimal configuration regarding both the light extraction and the intensity distribution. Marianne Consonni, Julien Routin, Anthony Piveteau, and Adrien Gasse Copyright © 2013 Marianne Consonni et al. All rights reserved. Active MMW/Terahertz Security System Based on Bessel Beams Mon, 27 May 2013 15:12:04 +0000 http://www.hindawi.com/journals/isrn.optics/2013/285127/ The novel concept of the security system based on THz Bessel beams is offered. The system is based on a novel THz diffractive optics for scanning the person (without the application of THz laser) and on a sensitive scheme for the detection of the reflected and scattered THz radiation. The development of enabling technology, namely, sensitive detector arrays and Millimeter wave/THz diffractive optics, will allow building compact, easy-to-use millimeter wave/THz imaging systems without expensive cost THz laser. The scanning properties of diffractive optics for Bessel beam are investigated. Igor Minin and Oleg Minin Copyright © 2013 Igor Minin and Oleg Minin. All rights reserved. Fossilized Teeth as a New Robust and Reproducible Standard for Polarization-Sensitive Optical Coherence Tomography Wed, 08 May 2013 10:39:45 +0000 http://www.hindawi.com/journals/isrn.optics/2013/391972/ A clinical need exists for a cheap and efficient standard for polarization sensitive optical coherence tomography (PS-OCT). We utilize prehistoric fossilized teeth from the Megalodon shark and European horse as an unconventional, yet robust standard. Given their easy accessibility and the microstructural consistency conferred by the process of fossilization, they provide a means of calibration to reduce error from sources such as catheter bending and temperature changes. We tested the maximum difference in birefringence values in each tooth and found the fossilized teeth to be fast and repeatable. The results were compared to measurements from bovine meniscus, tendon, and destroyed tendon, which were verified with histology. Christopher Vercollone, Bin Liu, and Mark E. Brezinski Copyright © 2013 Christopher Vercollone et al. All rights reserved. Terahertz Frequency Continuous-Wave Spectroscopy and Imaging of Explosive Substances Mon, 18 Mar 2013 14:17:27 +0000 http://www.hindawi.com/journals/isrn.optics/2013/419507/ Continuous-wave terahertz (THz) radiation spectroscopy was performed on high explosive materials using a tuneable optical parametric oscillator (OPO). Military grade, solid-phase, explosive substances, such as cyclotetramethylenetetranitramine (HMX), cyclotrimethylenetrinitramine (RDX), pentaerythritol tetranitrate (PETN), and composition-4, were spectrally scanned over the 0.7–1.9 THz frequency range under experimental conditions modeling that of “real-world” security screenings. Spectral peak locations and spectral line broadening effects were quantified using a Lorentz lineshape fit algorithm. The full-width half-maximum (FWHM) parameter computed by the Lorentz fit algorithm was shown to help in the identification of samples with broad and sparse spectral characteristics. A concealed explosives identification scheme was demonstrated through raster scan THz frequency radiation imaging at specific OPO tuning frequencies. Michael A. Startsev and Abdulhakem Y. Elezzabi Copyright © 2013 Michael A. Startsev and Abdulhakem Y. Elezzabi. All rights reserved. Microstructures in Polymer Fibres for Optical Fibres, THz Waveguides, and Fibre-Based Metamaterials Tue, 12 Feb 2013 09:46:30 +0000 http://www.hindawi.com/journals/isrn.optics/2013/785162/ This paper reviews the topic of microstructured polymer fibres in the fields in which these have been utilised: microstructured optical fibres, terahertz waveguides, and fibre-drawn metamaterials. Microstructured polymer optical fibres were initially investigated in the context of photonic crystal fibre research, and several unique features arising from the combination of polymer and microstructure were identified. This lead to investigations in sensing, particularly strain sensing based on gratings, and short-distance data transmission. The same principles have been extended to waveguides at longer wavelengths, for terahertz frequencies, where microstructured polymer waveguides offer the possibility for low-loss flexible waveguides for this frequency region. Furthermore, the combination of microstructured polymer fibres and metals is being investigated in the fabrication of metamaterials, as a scalable method for their manufacture. This paper will review the materials and fabrication methods developed, past and current research in these three areas, and future directions of this fabrication platform. Alexander Argyros Copyright © 2013 Alexander Argyros. All rights reserved. Infrared Transmission Characteristics and Laser Tissue Interaction of Albino Pigskin Using Pulsed NIR Laser Light Tue, 15 Jan 2013 08:41:10 +0000 http://www.hindawi.com/journals/isrn.optics/2013/451208/ This work explores near infrared transmission through albino pigskin and determines controllable factors that influence transmission efficiency. Pigskin samples of varying thicknesses were irradiated using a 1440 nm near-infrared laser diode, where a photodetector was used to measure the transmitted power, and a two-dimensional real time surface temperature distribution was recorded using infrared thermography. Results demonstrate that this technique could potentially lead to a noninvasive approach for enhancing wound healing. Hisham Abdussamad Abbas and Gregory E. Triplett Copyright © 2013 Hisham Abdussamad Abbas and Gregory E. Triplett. All rights reserved. Adaptive Optics for Visual Simulation Mon, 24 Dec 2012 09:32:49 +0000 http://www.hindawi.com/journals/isrn.optics/2012/104870/ A revision of the current state-of-the-art adaptive optics technology for visual sciences is provided. The human eye, as an optical system able to generate images onto the retina, exhibits optical aberrations. Those are continuously changing with time, and they are different for every subject. Adaptive optics is the technology permitting the manipulation of the aberrations, and eventually their correction. Across the different applications of adaptive optics, the current paper focuses on visual simulation. These systems are capable of manipulating the ocular aberrations and simultaneous visual testing though the modified aberrations on real eyes. Some applications of the visual simulators presented in this work are the study of the neural adaptation to the aberrations, the influence of aberrations on accommodation, and the recent development of binocular adaptive optics visual simulators allowing the study of stereopsis. Enrique Josua Fernández Copyright © 2012 Enrique Josua Fernández. All rights reserved. Feedback Control in Quantum Optics: An Overview of Experimental Breakthroughs and Areas of Application Mon, 17 Dec 2012 13:42:35 +0000 http://www.hindawi.com/journals/isrn.optics/2012/275016/ We present a broad summary of research involving the application of quantum feedback control techniques to optical setups, from the early enhancement of optical amplitude squeezing to the recent stabilisation of photon number states in a microwave cavity, dwelling mostly on the latest experimental advances. Feedback control of quantum optical continuous variables, quantum nondemolition memories, feedback cooling, quantum state control, adaptive quantum measurements, and coherent feedback strategies will all be touched upon in our discussion. Alessio Serafini Copyright © 2012 Alessio Serafini. All rights reserved. Quantum Field Theory of Dynamics of Spectroscopic Transitions by Strong Dipole-Photon and Dipole-Phonon Coupling Wed, 12 Dec 2012 15:54:05 +0000 http://www.hindawi.com/journals/isrn.optics/2012/390749/ Matrix-operator difference-differential equations for dynamics of spectroscopic transitions in 1D multiqubit exchange-coupled (para)magnetic and optical systems by strong dipole-photon and dipole-phonon coupling are derived within the framework of quantum field theory. It has been established that by strong dipole-photon and dipole-phonon coupling the formation of long-lived coherent system of the resonance phonons takes place, and relaxation processes acquire pure quantum character. It is determined by the appearance of coherent emission process of EM-field energy, for which the resonance phonon system is responsible. Emission process is accompanied by phonon Rabi quantum oscillation, which can be time-shared from photon quantum Rabi oscillations, accompanying coherent absorption process of EM-field energy. For the case of radio spectroscopy, it corresponds to the possibility of the simultaneous observation along with (para)magntic spin resonance, the acoustic spin resonance. Alla Dovlatova and Dmitri Yerchuck Copyright © 2012 Alla Dovlatova and Dmitri Yerchuck. All rights reserved. Probability Densities for Fluorescent Photons Emitted by a Two-State Atom Driven by a Laser Tue, 11 Dec 2012 09:30:15 +0000 http://www.hindawi.com/journals/isrn.optics/2012/745871/ Fluorescent photons emitted by a two-state atom in a laser beam are correlated. We have obtained the probability density for the emission of the th photon after a random initial time . It is shown that the correlations between the photons lead to a deviation from the poissonian value for this function (the probability density for independent events), although the deviation is not as significant as one may expect. Robertsen A. Riehle and Henk F. Arnoldus Copyright © 2012 Robertsen A. Riehle and Henk F. Arnoldus. All rights reserved. Advanced Nanomeasuring Techniques for Surface Characterization Mon, 03 Dec 2012 10:43:10 +0000 http://www.hindawi.com/journals/isrn.optics/2012/859353/ Advanced precise and accurate nanomeasurement techniques play an important role to improve the function and quality of surface characterization. There are two basic approaches, the hard measuring techniques and the soft computing measuring techniques. The advanced soft measuring techniques include coordinate measuring machines, roundness testing facilities, surface roughness, interferometric methods, confocal optical microscopy, scanning probe microscopy, and computed tomography at the level of nanometer scale. On the other hand, a new technical committee in ISO is established to address characterization issues posed by the areal surface texture and measurement methods. This paper reviews the major advanced soft metrology techniques obtained by optical, tactile, and other means using instruments, classification schemes of them, and their applications in the engineering surfaces. Furthermore, future trends under development in this area are presented and discussed to display proposed solutions for the important issues that need to be addressed scientifically. Salah H. R. Ali Copyright © 2012 Salah H. R. Ali. All rights reserved. Structural, Optical, and Luminescence Properties of Reactive Magnetron Sputtered Tungsten Oxide Thin Films Sat, 01 Dec 2012 11:09:56 +0000 http://www.hindawi.com/journals/isrn.optics/2012/801468/ Tungsten oxide (WO3) thin films were deposited on to unheated Corning glass and silicon substrates by RF magnetron sputtering of metallic tungsten target at various oxygen partial pressures in the range – Pa. The influence of oxygen partial pressure on the structure and surface morphology and the optical and photoluminescence properties of the films were investigated. X-ray diffraction studies revealed that the deposited films were amorphous in nature. Fourier transform infrared transmission spectra confirmed that the presence of stretching vibration of W-O-W and deformation of W-O bonds related to the WO3. The optical transmittance of the films at wavelengths >500 nm increased from 62% to 85% with the increase of oxygen partial pressure. The optical band gap of the films increased from 3.00 to 3.14 eV and the refractive index of the films decreased from 2.26 to 2.08 with the increase of oxygen partial pressure from to  Pa, respectively. The photoluminescence studies indicated that the intense blue emission which was assigned to band-to-band transition was observed at oxygen partial pressure of  Pa. V. Madhavi, P. Kondaiah, O. M. Hussain, and S. Uthanna Copyright © 2012 V. Madhavi et al. All rights reserved. Embedding N × N Crossbar Switches into ILLIAC(N, N − 1) Torus Networks for Optical Interconnection Networks Tue, 20 Nov 2012 08:20:43 +0000 http://www.hindawi.com/journals/isrn.optics/2012/218541/ A focus of research for crossbar switches has been to reduce the number of switch elements, each of which not only occupies a relatively large area but also costs a lot when implemented with optical devices. We point out that conventional crossbar switches, where is the switch size, actually function as switches and thus have redundant switch elements to be removed. We show that ILLIAC torus networks, which have a less number of switching elements than crossbar switches of an identical switch size, are equivalent to true crossbar switches. We describe in detail how the crossbar switches can be embedded into the equivalent torus networks. We also discuss switch control complexity of the equivalent torus networks and show that it can be reduced to (1). P. Selin and H. Obara Copyright © 2012 P. Selin and H. Obara. All rights reserved. Quantum Dynamics of Interacting Modes in Intracavity Third Harmonic Generation Process Wed, 14 Nov 2012 10:09:16 +0000 http://www.hindawi.com/journals/isrn.optics/2012/476817/ We study the quantum dynamics of the number of photons of the interacting modes, the dynamics of the quantum entropy, and the Wigner function of the states of the fundamental and the third harmonic modes for the process of intracavity third harmonic generation. It is shown that the quantum dynamics of the system strongly depends on the external resonant perturbation of the fundamental mode and on the coupling coefficient of the interacting modes. In the region of long interaction times, the modes of the field can be both in stable and in unstable states—depending on the above-mentioned quantities. In the paper, we also investigate the dynamics of transition of the system from stable to unstable states. Menua Gevorgyan and Saribek Gevorgyan Copyright © 2012 Menua Gevorgyan and Saribek Gevorgyan. All rights reserved.