SPATIAL PROPAGATION OF QUANTUM LIGHT IN NONLINEAR WAVEGUIDING DEVICES: THEORY AND APPLICATIONS

2012 ◽  
Vol 21 (03) ◽  
pp. 1250032 ◽  
Author(s):  
JESÚS LIÑARES ◽  
DAVID BARRAL ◽  
MARÍA C. NISTAL
Keyword(s):  
Field Strength ◽  
Light Propagation ◽  
Optical Field ◽  
Quantum States ◽  
Nonlinear Propagation ◽  
Quantum Dissipation ◽  
Mechanical Formulation ◽  
Spatial Propagation ◽  
Path Integral Method ◽  
Nonlinear Devices

We present the main theoretical results on spatial propagation of quantum light in nonlinear waveguiding devices together with a few applications. We show that the quantization of the classical momentum provides a consistent quantum mechanical formulation of both the linear and the nonlinear quantum light propagation in waveguiding devices. The momentum operator allows us to derive the correct spatial Heisenberg's equations for the forward and backward absorption and emission operators and consequently to analyze the spatial propagation in the multimode optical-field strength space. For that purpose we use the Feynman's path integral method in order to derive the quantum spatial optical propagators of different nonlinear waveguiding devices and accordingly to calculate the spatial propagation of the optical-field strength probability amplitude of quantum states in these nonlinear devices. Likewise, we present a preliminary and heuristic formulation of quantum dissipation in order to take into account the losses under spatial quantum propagation in lossy nonlinear waveguiding devices. It must be stressed that these optical-field strength probabilities have the advantage of being measured by homodyne techniques and therefore their theoretical analysis is of a remarkable interest in the optical characterization of quantum states obtained under linear and nonlinear propagation in waveguiding devices.

scholarly journals "SCHWINGER MODEL" ON THE FUZZY SPHERE

2010 ◽  
Vol 25 (37) ◽  
pp. 3151-3167 ◽  
Author(s):  
E. HARIKUMAR
Keyword(s):  
Partition Function ◽  
Field Strength ◽  
Dirac Operator ◽  
Path Integral ◽  
Integral Method ◽  
Gauge Fields ◽  
Fuzzy Sphere ◽  
Schwinger Model ◽  
Spinor Fields ◽  
Path Integral Method

In this paper, we construct a model of spinor fields interacting with specific gauge fields on the fuzzy sphere and analyze the chiral symmetry of this "Schwinger model". In constructing the theory of gauge fields interacting with spinors on the fuzzy sphere, we take the approach that the Dirac operator Dq on the q-deformed fuzzy sphere [Formula: see text] is the gauged Dirac operator on the fuzzy sphere. This introduces interaction between spinors and specific one-parameter family of gauge fields. We also show how to express the field strength for this gauge field in terms of the Dirac operators Dq and D alone. Using the path integral method, we have calculated the 2n-point functions of this model and show that, in general, they do not vanish, reflecting the chiral non-invariance of the partition function.

Optical field-strength polarization of two-mode single-photon states

2010 ◽  
Vol 31 (5) ◽  
pp. 991-1005 ◽  
Author(s):  
J Liñares ◽  
M C Nistal ◽  
D Barral ◽  
V Moreno
Keyword(s):  
Field Strength ◽  
Single Photon ◽  
Optical Field ◽  
Photon States

Highly Accurate Computer Modeling of Light Propagation in Inhomogeneous, Anisotropic Medium for the Acousto-Optical Phenomenon

2008 ◽  
Vol 55 ◽  
pp. 164-168
Author(s):  
Gabor Mihajlik ◽  
P. Maák ◽  
A. Barócsi ◽  
P. Richter
Keyword(s):  
Field Distribution ◽  
Light Propagation ◽  
Beam Propagation Method ◽  
Beam Propagation ◽  
Optical Field ◽  
Bragg Diffraction ◽  
Computational Time ◽  
Step Size ◽  
Optical Phenomenon ◽  
Optically Inhomogeneous Medium

We present a novel numerical model that simulates the anisotropic Bragg diffraction in optically anisotropic (uniaxial) acousto-optical devices. We use a non-paraxial vectorial beam propagation method adapted to optically inhomogeneous medium and arbitrary optical field distribution. The principal idea of our solving method is that since the amplitude of the spatial variation of the refractive index caused by the acoustic wave is relatively small, we can consider it as a perturbation and iterate to the exact solution of the wave equation describing the propagation of the optical field distribution. To describe anisotropic diffraction with polarization rotation, we use a fully vectorial beam propagation method (BPM) where the accuracy depends on the relative step size. The results converge rapidly to fulfill energy conservation (up to 10–3 with less than an hour of computational time). We show that the calculated angles, the space dependent intensity and polarization variations of the diffracted beams agree accurately with those predicted by theory and experiment, under Bragg diffraction condition, in various acousto-optic configurations.

A QUANTUM MECHANICAL — ELECTRODYNAMICAL APPROACH TO NONLINEAR PROPERTIES: APPLICATION TO OPTICAL POWER LIMITING WITH PLATINUM-ORGANIC COMPOUNDS

2007 ◽  
Vol 16 (02) ◽  
pp. 157-169 ◽  
Author(s):  
ALEXANDER BAEV ◽  
PONTUS WELINDER ◽  
ROBERT ERLANDSSON ◽  
JOHAN HENRIKSSON ◽  
PATRICK NORMAN ◽  
...  
Keyword(s):  
Cross Sections ◽  
Degrees Of Freedom ◽  
Light Propagation ◽  
Optical Power ◽  
Photon Absorption ◽  
Nonlinear Propagation ◽  
Quantum Mechanical ◽  
Strong Light ◽  
Light Pulses ◽  
Optical Power Limiting

Light propagation in a medium is sensitively dependent on the shape and intensity of the optical pulse as well as on the electronic and vibrational structure of the basic molecular units. We review in this paper the results of systematic studies of this problem for isotropic media. Our theoretical approach—the quantum mechanical–electrodynamical (QMED) approach—is based on a quantum mechanical account of the many-level electron-nuclear medium coupled to a numerical solution of the density matrix and Maxwell's equations. This allows us to accommodate a variety of nonlinear effects which accomplish the propagation of strong light pulses. Particular attention is paid to the understanding of the role of coherent and sequential excitations of electron-nuclear degrees of freedom. The QMED combination of quantum chemistry with classical pulse propagation enables us to estimate the optical transmission from cross sections of multi-photon absorption processes and from considerations of propagation effects, saturation and pulse effects. Results of the theory suggest that in the nonlinear regime, it is often necessary to simultaneously account for coherent one-step and incoherent step-wise multi-photon absorption, as well as for off-resonant excitations even when resonance conditions prevail. The dynamic theory of nonlinear propagation of a few interacting intense light pulses is highlighted here in a study of the optical power limiting with platinum-organic molecular compounds.

scholarly journals Optically-driven switching of a planar nematic liquid crystal cell with parallel rubbing

2017 ◽  
Vol 9 (2) ◽  
pp. 39
Author(s):  
Varsenik Nersesyan
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Nematic Liquid Crystal ◽  
Tilt Angle ◽  
Light Propagation ◽  
Domain Walls ◽  
Optical Field ◽  
Liquid Crystal Cell ◽  
Crystal Cell ◽  
Order Of Magnitude

This letter reports on the switching of a planar nematic liquid crystal cell with parallel rubbing of the alignment layers, under the application of a voltage, when there is initially an optical field. The voltage application over the liquid crystal in such a cell leads normally to the formation of multiple domains because there is the two switching directions are equivalent. However, an incident optical field under an angle will locally reorient the director and break the symmetry between the equivalent switching directions. The subsequent application of a voltage pulse amplifies the tilt angle and leads to the formation of a dominant domain, with an order of magnitude larger size than the optical beam profile. Several switching conditions are demonstrated for different incident angles of the beam. It is shown that the final switching direction of the entire cell is determined by the tilt angle of the optical field. The lensing effects due to the modified director distribution in the domain walls is analyzed qualitatively. Full Text: PDF ReferencesI. C. Khoo, Liquid crystals (2nd ed. Hoboken (NJ), Wiley, 2007) CrossRef A. Zolotko, V. Kitaeva, N. Kroo et al. OCBP. JETP Lett. 32, 158?162 (1980). DirectLink J. Beeckman, K. Neyts, X. Hutsebaut X, et al. "Simulations and experiments on self-focusing conditions in nematic liquid-crystal planar cells", Opt Express, 12, 1011? 1018 (2004). CrossRef M. Peccianti, C. Conti, G. Assanto, et al. "Electrically assisted self-confinement and waveguiding in planar nematic liquid crystal cells", Appl. Phys. Lett. 77, 7 ? 9 (2000). CrossRef N. Kravets, A. Piccardi, A. Alberucci et al, "Bistability with Optical Beams Propagating in a Reorientational Medium", Phys. Rev. Lett. 113, 023901 (2014) CrossRef A. Piccardi, N. Kravets, A. Alberucci et al, "Voltage-driven beam bistability in a reorientational uniaxial dielectric", APL Photonics 1, 011302 (2016). CrossRef V. Nersesyan, T. Brans, F. Beunis, R. Drampyan , J. Beeckman, K. Neyts, "Light-controlled reorientation of nematic liquid crystal driven by an electric field", Liquid crystals, 43, 1422-1430 (2016). CrossRef J. Beeckman, K. Neyts, W. Cort, et al. "Non-linear light propagation and bistability in nematic liquid crystals", Proc SPIE 7414, 74140K (2009). CrossRef

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