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