10 research outputs found
Nonlocal reflection by photonic barriers
The time behaviour of microwaves undergoing partial reflection by photonic
barriers was measured in the time and in the frequency domain. It was observed
that unlike the duration of partial reflection by dielectric layers, the
measured reflection duration of barriers is independent of their length. The
experimental results point to a nonlocal behaviour of evanescent modes at least
over a distance of some ten wavelengths. Evanescent modes correspond to
photonic tunnelling in quantum mechanics.Comment: 8 pages, 5 figure
Superluminal Localized Solutions to Maxwell Equations propagating along a waveguide: The finite-energy case
In a previous paper of ours [Phys. Rev. E64 (2001) 066603, e-print
physics/0001039] we have shown localized (non-evanescent) solutions to Maxwell
equations to exist, which propagate without distortion with Superluminal speed
along normal-sized waveguides, and consist in trains of "X-shaped" beams. Those
solutions possessed therefore infinite energy. In this note we show how to
obtain, by contrast, finite-energy solutions, with the same localization and
Superluminality properties. [PACS nos.: 41.20.Jb; 03.50.De; 03.30.+p; 84.40.Az;
42.82.Et. Keywords: Wave-guides; Localized solutions to Maxwell equations;
Superluminal waves; Bessel beams; Limited-dispersion beams; Finite-energy
waves; Electromagnetic wavelets; X-shaped waves; Evanescent waves;
Electromagnetism; Microwaves; Optics; Special relativity; Localized acoustic
waves; Seismic waves; Mechanical waves; Elastic waves; Guided gravitational
waves.]Comment: plain LaTeX file (12 pages), plus 10 figure
The Exact Correspondence between Phase Times and Dwell Times in a Symmetrical Quantum Tunneling Configuration
The general and explicit relation between the phase time and the dwell time
for quantum tunneling or scattering is investigated. Considering a symmetrical
collision of two identical wave packets with an one-dimensional barrier, here
we demonstrate that these two distinct transit time definitions give connected
results where, however, the phase time (group delay) accurately describes the
exact position of the scattered particles. The analytical difficulties that
arise when the stationary phase method is employed for obtaining phase
(traversal) times are all overcome. Multiple wave packet decomposition allows
us to recover the exact position of the reflected and transmitted waves in
terms of the phase time, which, in addition to the exact relation between the
phase time and the dwell time, leads to right interpretation for both of them.Comment: 11 pages, 2 figure
Cdse/zns Quantum Dots Doped Microstructured Plastic Optical Fibres (mpofs) For Visible Spectra Amplification In The Green Window
This paper reports the transmission and fluorescence measurements of star-type PMMA mPOFs doped with CdSe/ZnS quantum-dots. The latter shows absorption at 509 nm and fluorescence at 529 nm wavelengths when diluted in toluene. Such mPOFs are intended to be a visible optical amplifier media in the 520 nm wavelength channel of PMMA POF links. The expected fluorescence emission is quite different of ~555 nm as measured with the doped mPOFs.151155Knowledge Development for POF,POF Application Center,Sojitz Corporation,Hamamatsu Photonics,OptogearZiemann, O., Krauser, J., Zamzow, P.E., Daum, W., POF Handbook - Optical Short Range Transmission Systems (2008), (2nd ed., Springer: Berlin)Kuzyk, M.G., Polymer Fiber Optics: Materials, Physics and Applications (2007), chapter 6, (Taylor & Francis)Technical Bulletin (2009), TBCDG0914PC33-01, Attenuation, PFU-CD1001-22-E and PMU-CD1001-22-E, July 14, Toray IndustriesWeinert, A., Plastic Optical Fibers: Principles, Components and Installation (1999), p. 40. , (Siemens)Ribeiro, R.M., Barbero, A.P.L., Medeiros, D.S.V., Ruas, P.H.D., Barbosa, L.C., Chillcce, E.F., Gonzáles, R.E.R., CdSe/ZnS Quantum Dots Doped Photonic Plastic Optical Fiber for Visible Spectra Amplification (2010), Proceedings of 19th ICPOF, October 19-21, Yokohama, JapanChillcce, E.F., Faustino, W.M., Jacob, G.J., Rodriguez, E., Cesar, C.L., Barbosa, L.C., Europium-doped optical fibers used as radiation sensors (2007), Proceedings of SPIE Newsroom, 20 MayEvident Technologies http//www.evidenttech.comYu, H.C.Y., Argyros, A., Leon-saval, S.G., Barton, G., Characterisation of quantum dot photoluminescence in polymer optical fibres (2009), Proceedings of 18th ICPOF, September 9-11, Sydney, Australia, paper S2_2
Advances in the development of simulation tools for integrated optics devices: FDTD, BPM, and mode solving techniques
In the present paper we review the state of the art of two complementary propagation techniques with applications integrated optics device modeling: the Finite-Difference Time- Domain and the Beam Propagation Method. In both cases we focus its on their main features such as the types of propagation schemes and the material effects that can be modeled.In addition, we also consider a 2D mode solver based on a complex root finding procedure - a representative rnode solving technique that is of significant interest for design and modeling of leaky mode based devices. Each of the methods is illustrated with appropriate simulation examples of devices and waveguide structures being of current research interest: photonic band gap structures, waveguide gratings, ARROW waveguides etc. The selected examples show the power of the methods as well as the consistency and the complementarity of their results when applied together
Advances in the development of simulation tools for integrated optics devices: FDTD, BPM and mode solving techniques
In the present paper we review the state of the art of two complementary propagation techniques with applications for integrated optics device modeling: The Finite-Difference Time-Domain and the Beam Propagation Method. In both cases we focus on their main features such as the types of propagation schemes and the material effects that can be modeled. In addition, we also consider a 2D mode solver based on a complex root finding procedure-a representative mode solving technique that is of significant interest for design and modeling of leaky mode based devices. Each of the methods is illustrated with appropriate simulation examples of devices and waveguide structures being of current research interest: photonic band gap structures, waveguide gratings, ARROW waveguides etc. The selected examples show the power of the methods as well as the consistency and the complementarity of their results when applied together