European Physical Journal B (14346028)36(1)pp. 115-118
A new type of noised induced phase transitions is proposed. It occurs in noisy systems with dynamical traps. Dynamical traps are regions in the phase space where the regular "forces" are depressed substantially. By way of an example, a simple oscillatory system {x,v = x} with additive white noise is considered and its dynamics is analyzed numerically. The dynamical trap region is assumed to be located near the x-axis where the "velocity" v of the system becomes sufficiently low. The meaning of this assumption is discussed. The observed phase transition is caused by the asymmetry in the residence time distribution in the vicinity of zero value "velocity". This asymmetry is due to a cooperative effect of the random Langevin "force" in the trap region and the regular "force" not changing the direction of action when crossing the trap region. © EDP Sciences, Società Italiana di Fisica, and Springer-Verlag 2003.
Proceedings of SPIE - The International Society for Optical Engineering (1996756X)5249pp. 249-260
A systematic design method for quasi-symmetrical wide angle systems is presented. The method starts with thin lens predesign of half of the system using most available glasses. The aperture stop position is determined for reducing astigmatism and the system is made symetrical about it for eliminating Coma, Lateral colour and Distortion. Finally the system is optimized using Eikonal software for infinite conjugate.
Journal of Modern Optics (13623044)51(13)pp. 1963-1982
A method for astigmatism calculations along any skew ray is presented. This is useful in the case of extremely wide angle optical systems (and not only imaging systems), where skew ray aberrations are most dominant, but it is essential in the case of systems which are not rotationally symmetric, where all the rays may be skew. Equations relating the position of the astigmatic foci before and after refraction or reflection are derived from the analysis of infinitesimal wave fronts in the immediate neighbourhood of the point of incidence of any ray, but particularly the central ray of any pencil on an optical surface. The method is then illustrated and checked with representative numerical examples. © 2004 Taylor & Francis Group, LLC.
Journal of the Physical Society of Japan (13474073)73(9)pp. 2413-2423
Temporal evolution of atomic properties including the population inversion and quantum fluctuations of atomic dipole variables are discussed in three variants of the two-photon q-deformed Jaynes-Cummings model. The model is based on the generalized deformed oscillator algebra, [Â,Â+] = (N̂ + 1)f2(N + 1) - N̂f2(N̂) in which f(N̂) as a function of number operator N̂ determines not only the intensity dependence of atom-field coupling, when the model Hamiltonian is expressed in terms of non-deformed field operators, but also the structure of initial state of the radiation field. With the field initially being in three different types of q-deformed coherent states, each of them corresponding to a particular form of the function f(N̂), the quantum collapse and revival effects as well as atomic dipole squeezing are studied for both on- and off-resonant atom-field interaction. Particularly, it is shown that for nonzero detuning the atomic inversion exhibits superstructures, which are absent in the non-deformed Jaynes-Cummings model, and the magnitude of dipole squeezing may be increased. © 2004 The Physical Society of Japan.
Journal of Physics B: Atomic, Molecular and Optical Physics (09534075)37(16)pp. 3321-3338
The Faddeev-Watson-Lovelace (FWL) treatment, in a second-order approximation, and an active electron model have been applied to calculate the single-electron capture differential cross sections from K-, L- and M-shells of many-electron atoms by protons at medium and high (but non-relativistic) impact energies. The radial part of the wavefunction for the active electron was obtained by constructing suitable bases from merging hyperbolic cosine functions with Slater-type radial ones. Converting the Schrödinger-like equation obtained from Hartree-Fock theory gives the effective potential, which is experienced by the active electron in the target atom. A simple analytic radial function composed of a Coulomb and a Yukawa potential was fitted to the effective potential. Near-the-shell two-body T-matrices, electronic-nuclear and inter-nuclear partial amplitudes are calculated to obtain the electron capture differential cross sections between various shells of the target atom and the ground state of atomic hydrogen formed, Theoretical results are compared with the available experimental data on helium, neon and argon atoms at different energies.
Progress of Theoretical Physics (13474081)112(5)pp. 797-809
Considering a simple generalization of the (p, q)-deformed boson oscillator algebra, which leads to a two-parameter deformed bosonic algebra in an infinite dimensional subspace of the harmonic oscillator Hilbert space without first finite Fock states, we establish a new harmonic oscillator realization of the deformed boson operators based on the Bogoliubov (p, q)-transformations. We obtain exact expressions for the transformation coefficients and show that they depend on arbitrary functions of p and q which can be interpreted as the parameters of the (p, q)-deformed GL(2, C) group. We also examine the existence and structure of the corresponding deformed Fock-space representation for our problem.
Applied Optics (21553165)43(35)pp. 6481-6486
A compact mid-infrared (MIR) laser spectrometer based on difference-frequency generation (DFG) is applied as a portable and sensitive gas sensor for industrial process control and pollutant monitoring. We demonstrate the performance of such a MIR DFG gas sensor by recording the absorption spectra of the carbon monoxide (CO) P(28) absorption line in the atmosphere of a gas-fired glass melting furnace. For a gas temperature of approximately 1100°C, the CO concentration in the recuperator channel is measured to be 400 parts per million. © 2004 Optical Society of America.
Proceedings of SPIE - The International Society for Optical Engineering (1996756X)5249pp. 740-745
The different methods of optical systems' optimization such as Newton and Least Squares along with their modification are discussed. Monte-Carlo technique as an statistical method which can overcome the shortcoming of those classic methods (such as the rate of convergence, the possibility of finding the overall minimum and avoiding local minima) is presented and compared with the other ones. An numerical example is presented to verify the method.
Wondraczek, L.,
Heide, G.,
Frischat, G.H.,
Khorsandi, A.R.,
Willer, U.,
Schade w., W. Glass Science and Technology (09467475)77(2)pp. 68-76
Laser spectroscopic diagnostics of combustion species at elevated temperature has shown considerable progress during the last years and decades. Particularly, techniques of mid-infrared absorption spectroscopy using fundamental rotational/vibrational transitions offer potentially great sensitivity and selectivity for combustion control. However, applications are still limited to mostly laboratoryscale investigations, which is mainly due to drawbacks of light sources and beam guidance materials. On the other hand, many efforts are made to facilitate industrial application. In this context, the relevance of mid-infrared absorption spectroscopy for in situ monitoring of minor species in glass melting furnaces is obvious, too. The present paper gives a general review of available techniques and their impact on emission diagnostics in the glass industry, considering conventional as well as emerging light sources, detectors, peripheral devices and spectroscopic techniques.
Wondraczek, L.,
Heide, G.,
Frischat, G.H.,
Khorsandi, A.R.,
Willer, U.,
Schade w., W. Glass Science and Technology (09467475)77(3)pp. 131-136
Emerging techniques of mid-infrared absorption spectroscopy offer potentially great sensitivity and selectivity for combustion control and emission monitoring. Because of that, a difference frequency based mid-infrared absorption spectrometer has been considered for application in the glass industry. Based on preliminary tests within laboratory conditions, a spectrometer which operates at wavelengths around 5 μm was applied to online monitoring of the atmosphere of a gas fired glass melting furnace. The CO concentration was measured in order to demonstrate the feasibility of a mid-infrared absorption spectrometer for process control in the glass industry. A series of measurements was performed in situ as well as crossing the recuperator entry, resulting in general advice on the construction of a prototype device.
Wondraczek, L.,
Khorsandi, A.R.,
Willer, U.,
Heide, G.,
Schade w., W.,
Frischat, G.H. Combustion and Flame (00102180)138(1-2)pp. 30-39
Three-dimensional imaging of minor combustion species is of great interest for combustion engineering, process control and environmental analysis. On the other hand, difference frequency generation (DFG) based continuous wave (cw) laser sources offer a compact and low-cost alternative light source for high resolution spectroscopy. In this work, difference frequency generation (DFG) laser light sources are used in the mid infrared (MIR) for the optical tomography of combustion products, such as carbon monoxide, in laminar CH 4/air flames on a flat flame burner. The combination of DFG MIR spectroscopy and computerized tomography is shown to offer great potential for laminar flames, as well as environmental monitoring. © 2004 The Combustion Institute. Published by Elsevier Inc. All rights reserved.
Optics InfoBase Conference Papers (21622701)
The P(28) line is used to detect carbon monoxide directly in the atmosphere of a glass furnace. A concentration of 300 ppm is found, in good agreement with conventional measurements in the exhaust gas stream. © 2003 Optical Society of America.
Journal of Physics A: Mathematical and General (03054470)37(9)pp. 3225-3240
In this paper, we introduce a new family of photon-added as well as photon-depleted q-deformed coherent states related to the inverse q-boson operators. These states are constructed via the generalized inverse q-boson operator actions on a newly introduced family of q-deformed coherent states (Quesne C 2002 J. Phys. A: Math. Gen. 35 9213) which are defined by slightly modifying the maths-type q-deformed coherent states. The quantum statistical properties of these photon-added and photon-depleted states, such as quadrature squeezing and photon-counting statistics, are discussed analytically and numerically in the context of both conventional (nondeformed) and deformed quantum optics.
Canadian Journal of Physics (00084204)82(8)pp. 623-646
By introducing a generalization of the (p, q)-deformed boson oscillator algebra, we establish a two-parameter deformed oscillator algebra in an infinite-dimensional subspace of the Hubert space of a harmonic oscillator without first finite Fock states. We construct the associated coherent states, which can be interpreted as photon-added deformed states. In addition to the mathematical characteristics, the quantum statistical properties of these states are discussed in detail analytically and numerically in the context of conventional as well as deformed quantum optics. Particularly, we find that for conventional (nondeformed) photons the states may be quadrature squeezed in both cases Q = pq < 1, Q = pq > 1 and their photon number statistics exhibits a transition from sub-Poissonian to super-Poissonian for Q < 1 whereas for Q > 1 they are always sub-Poissonian. On the other hand, for deformed photons, the states are sub-Poissonian for Q > 1 and no quadrature squeezing occurs while for Q < 1 they show super-Poissonian behavior and there is a simultaneous squeezing in both field quadratures.
Progress of Theoretical Physics (13474081)112(5)pp. 811-829
We construct a family of deformed boson coherent states associated with deformed Bogoliubov (p, q)-transformations in an infinite dimensional subspace of the harmonic oscillator Hilbert space without first finite Fock states. We investigate their over-completeness and show that they allow the resolution of unity in the form of an ordinary integral (for Q = pq < 1) or a generalized Q-deformed one (for Q = pq > 1). We study in detail analytically and numerically some of the geometrical and physical properties of these deformed coherent states in the context of deformed quantum optics. In particular, we show that for Q > 1 they exhibit sub-Poissonian statistics and no quadrature squeezing occurs while for Q < 1 their photon number statistics is super-Poissonian and there is a simultaneous squeezing in both field quadratures (double squeezing). Additionally, by a natural extension, we construct the corresponding multi-photon deformed coherent states and investigate their properties.
Journal of Physics A: Mathematical and General (03054470)37(21)pp. 5649-5660
We establish some of the properties of the states interpolating between number and coherent states denoted by |n〈λ; among them are the reproduction of these states by the action of an operator-valued function on |n〈 (the standard Fock space) and the fact that they can be regarded as f -deformed coherent bound states. In this paper we use them as the basis of our new Fock space which in this case is not orthogonal but normalized. Then by some special superposition of them we obtain new representations for coherent and squeezed states in the new basis. Finally the statistical properties of these states are studied in detail.
Journal of Physics A: Mathematical and General (03054470)37(15)pp. 4407-4422
Starting with the canonical coherent states, we demonstrate that all the so-called nonlinear coherent states, used in the physical literature, as well as large classes of other generalized coherent states, can be obtained by changes of bases in the underlying Hubert space. This observation leads to an interesting duality between pairs of generalized coherent states, bringing into play a Gelfand triple of (rigged) Hubert spaces. Moreover, it is shown that in each dual pair of families of nonlinear coherent states, at least one family is related to a (generally) non-unitary projective representation of the Weyl-Heisenberg group, which can then be thought of as characterizing the dual pair.
Journal of Physics A: Mathematical and General (03054470)37(33)pp. 8111-8127
Considering some important classes of generalized coherent states known in the literature, we demonstrated that all of them can be created via conventional methods, i.e. the 'lowering operator eigenstate' and the 'displacement operator' techniques using the 'nonlinear coherent states' approach. As a result we obtained a 'unified method' to construct a large class of coherent states which have already been introduced by different prescriptions.
Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers (13474065)43(2)pp. 611-620
In this paper, a detailed theoretical treatment of the three dimensional photothermal deflection, under modulated cw excitation, is presented for a three layer system (backing-solid sample-fluid). By using a technique based on Green's function and integral transformations we find the explicit expressions for laser induced temperature distribution function and the photothermal deflection of the probe beam. Numerical analysis of those expressions for certain solid samples shows that the laser induced temperature of the sample surface, the effective thermal length and the deflection signal and its width decrease with increasing modulation frequency. Furthermore, increasing the diffusivity/conductivity of solid sample results in a decrease in the deflection signal intensity and slight increase in the signal width. Finally, we find that the focal length of the photothermal lens in normal direction is much greater than that of in tangential direction.
European Physical Journal D (14346060)32(3)pp. 397-408
In this paper we propose a theoretical scheme to show the possibility of generating various families of nonlinear (f-deformed) coherent states of the radiation field in a micromaser. We show that these states can be provided in a lossless micromaser cavity under the weak Jaynes-Cummings interaction with intensity-dependent coupling of large number of individually injected two-level atoms in a coherent superposition of the upper and lower states. In particular, we show that the so-called nonlinear squeezed vacuum and nonlinear squeezed first excited states, as well as the even and odd nonlinear coherent states can be generated in a two-photon micromaser. © EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2005.
Journal of Mathematical Physics (10897658)46(4)
Using the analytic representation of the so-called Gazeau-Klauder coherent states (CSs), we shall demonstrate that how a new class of generalized CSs, namely the family of dual states associated with theses states, can be constructed through viewing these states as temporally stable nonlinear CSs. Also we find that the ladder operators, as well as the displacement type operator corresponding to these two pairs of generalized CSs, may be easily obtained using our formalism, without employing the supersymmetric quantum mechanics (SUSYQM) techniques. Then, we have applied this method to some physical systems with known spectrum, such as Pöschl-Teller, infinite well, Morse potential and hydrogenlike spectrum as some quantum mechanical systems. Finally, we propose the generalized form of the Gazeau-Klauder CS and the corresponding dual family. © 2005 American Institute of Physics.
European Physical Journal B (14346028)44(1)pp. 63-70
An oscillator chain with dynamical traps and additive white noise is considered. Its dynamics are studied numerically. New type nonequilibrium phase transitions are shown to arise in the case when the trap effect is pronounced. Locally they manifest themselves in distortion of the symmetry of particle arrangement. Depending on the system parameters, the particle arrangement is characterized by the corresponding distributions taking either a bimodal form, or a twoscale one, or a unimodal onescale form that, however, deviates substantially from the Gaussian distribution. The particle velocities also exhibit a number of anomalies, in particular, their distribution can be extremely wide or take a quasi-cusp form. A large number of various cooperative structures and superstructures are found in the visualized time patterns. In a certain sense their evolution is independent of the individual particle dynamics, enabling us to regard them as dynamical phases. © EDP Sciences/Società Italiana di Fisica/Springer-Verlag 2005.
International Journal of Theoretical Physics (00207748)44(9)pp. 1573-1585
The classical and quantum dynamic of a non-linear charged vibrating string and its interaction with quantum vacuum field is investigated. Some probability amplitudes for transitions between vacuum field and quantum states of the string are obtained. The effect of non-linearity on some probability amplitudes is investigated and finally the correct equation for string containing the vacuum and radiation reaction field is obtained. © 2005 Springer Science+Business Media, Inc.
Modern Physics Letters A (02177323)20(39)pp. 3025-3034
By taking a Klein-Gordon field as the environment of a harmonic oscillator and using a new method for dealing with quantum dissipative systems (minimal coupling method), we find out the quantum dynamics and radiation reaction for a quantum damped harmonic oscillator. Applying perturbation method, we obtain some transition probabilities indicating the way energy flows between oscillator, reservoir and quantum vacuum. © World Scientific Publishing Company.
Optics InfoBase Conference Papers (21622701)
Mid-infrared laser radiation at 7.9 μm is generated by DFG in AgGaS2 for the detection of explosives TNT, RDX, PETN, and TATP. Fiber coupled absorption and evanescent field sensors are developed for remote detection. ©2004 Optical Society of America.
A new type of noised-induced phase transitions that should occur in systems of elements with motivated behavior is considered. By way of an example, a simple oscillatory system {x, ν = ẋ} with additive white noise is analyzed numerically. A chain of such oscillators is also studied in brief.
Few-Body Systems (01777963)39(1-2)pp. 11-25
Off-the-shell anomalous factors of the two-body Coulomb transition matrices appear in the integral form of the Faddeev second-order nuclear-electronic amplitude, for proton-hydrogen charge transfer scattering in a typical nlm → n′l′m′ transition. A symmetric-impulse approximation (SIA) is applied to eliminate these factors and an induction method is proposed to analytically calculate the remaining integrals. The nuclear-electronic amplitude is derived for the general case, and for totally symmetric collisions, in terms of generalized hypergeometric functions of two variables, F 4, and of one variable, 3 F 2, respectively. The angular distribution of the second-order nuclear-electronic charge transfer amplitude shows the Thomas mechanism as a peak or a hump for symmetric and asymmetric collisions. There also exists a peak in the forward angular distribution of the second-order nuclear-electronic amplitude, which partly cancels the kinematic peak in the angular distribution of the charge transfer differential cross sections.
Optics InfoBase Conference Papers (21622701)
Micro lens lithography does not impose any limit on the mask and on the size of wafer area. The design details of a lens system for micro lens lithography are discussed in this paper. This system contains three micro lens arrays with aspheric surfaces. We simulate and optimize this system and increased resolution with geometrical and diffraction-based methods and using available commercial optical design software. © 2006 Optical Society of America.
