Abstracts
100 years of photosensitivity in optical glasses
Raman Kashyap
Ecole Polytechnique de Montréal (Canada)
Fundamentals of photosensitivity
B.Poumellec
Université de Paris Sud, Orsay, France
Abstract:
Are stresses and stress changes in optical fibres the
key to understanding the phenomenon of photosensitivity
H.G.Limberger
Institute of Imaging and Applied Optics - EPFL (Switzerland)
Abstract:
UV-written Bragg gratings
Morten Ibsen
ORC, University of Southampton (UK)
Abstract:
References:
Fibre gratings in sensing applications
David Webb
Aston University (UK)
Abstract:
Poling of glass
Walter Margulis
ACREO (Sweden)
Abstract:
New directions and the future of UV-written
technologies
Marc Douay
Universite des Sciences et Technologies de Lille (France)
Abstract:
Advances in ultrashort pulse lasers
Peter G.Kryukov
Fiber, Russian Academy of Sciences (Russia)
Abstract:
Breaking the limits in glass: From quantum
interference to fs nanostructuring
Peter Kazansky
University of Southampton (UK)
Abstract:
References:
Laser engineering in nano-structured glasses
Gerhard Seifert
Martin-Luther-University Halle (Germany)
Abstract:
Raman fiber lasers: breakthrough in laser physics
E.M.Dianov, A.M.Prokhorov
General Physics Institute RAS (Russia)
Abstract:
High-power ultrafast fiber lasers: new horizons and
applications
Anatoly Grudinin
FIANIUM LTD., (UK)
Abstract:
Extreme Nonlinear Optics: Multiphoton X-Ray Photonics
and Applications
Emily Gibson, Ariel Paul, Ron Tobey, Nick Wagner, Tim
Lei, Ivan Christov, John Gland, Thomas Feurer, Keith Nelson, Henry Kapteyn,
Margaret Murnane
JlLA University of Colorado at Boulder (USA)
Abstract:
References:
Quantum information and Wavelength Scale Structures
Prof John G.Rarity
Bristol University (UK)
Abstract:
References:
Aspects of the quantum theory of near-field optics.
Ole Keller
Aalborg University Centre (Denmark) .
Abstract:
Quantum Computing using Electron Spin in Group IV
Semiconductors
Eli Yablonovitch
UCLA Electrical Engineering Department (USA)
Abstract:
The atom chip
Ron Folman
Ben-Gurion University (Israel)
Abstract:
Experimental nano-optics: principles and applications
Anatoly V.Zayats
The Queen's University of Belfast (UK)
Abstract:
Further reading:
Optical trapping/tweezing of microscopic objects and
atoms
Kishan Dholakia
University of St. Andrews (UK)
Abstract:
Supercontinuum Generation in Photonic Crystal Fibre
John Dudley
Universite de Franche-Comte (France)
Abstract:
Negative refraction opens new doors in optics
John Pendry
Imperial College London (UK)
Abstract:
Direct UV-written waveguides in tin-doped multicomponent
silicate glass
Frank Knappe1, Yvonne Menke2, Fabrice
Grézaud1, Hagen Renner1, Monica Ferraris2,
Ernst Brinkmeyer1
1. Technische Universitat Hamburg-Harburg, Optical
Communication Technology, Eißendorfer Str. 40, D-21073 Hamburg, Germany
Abstract:
Physical Asymmetry of Defects Induced by Femtosecond
Laser Irradiation in Silica
François Busque, Suzanne Lacroix, Raman Kashyap, Michel Meunier
Ecole polytechnique, Montréal, Canada
Abstract:
Waveguide fabrication in bismuthate glasses using femtosecond
laser pulses
Weijia Yang, Erica Bricchi and Peter G.Kazansky
Optoelectronics Research Centre , University of Southampton,
Southampton SO17 1BJ, UK Tel. +44(0)-23-8059 2086, Fax: +44(0)-23-8059 3142,
e-mail: wey@orc.soton.ac.uk
Abstract:
Extraordinary stability of femtosecond direct written
structures
Erica Bricchi and Peter G.Kazansky
Optoelectronics Research Centre, University of Southampton,
Southampton SO17 1BJ, UK Tel.: +44 023 8059 3142, +44 023 8059 3143, erb@orc.soton.ac.uk
Abstract:
Fiber Optics for Quantum Computers
S.Helsby, H.F.Powell, P.Horak, B.G.Klappauf, M.Ibsen and P.Kazansky
Optoelectronics Research Centre, University of Southampton,
Southampton, SO17 1BJ. hfp@orc.soton.ac.uk
Abstract:
Investigation into the Photosensitivity of
germanium-free antimony codoped alumino-silicate optical fibres
N.Y.Voo, J.K.Sahu, M.R.Mokhtar, D.N.Payne and M.Ibsen
Optoelectronics Research Centre, University of Southampton,
SO17 1BJ, Southampton, UK E-mail nvv@orc.soton.ac.uk, jks@orc.soton.ac.uk
Abstract:
All solid photonic band-gap fibres
Feng Luan, Alan M.George, P.E.Hedley, D.M.Bird, J.C.Knight
and P.St.J.Russell
Optoelectronics Group, Department of Physics, Univ. of Bath,
Bath, BA2 7AY, United Kingdom pypfl@bath.ac.uk
Abstract:
Hypersensitisation in germanosilicate optical fibres
Albert Canagasabey1,2 John Canning1
1. Optical Fibre Technology Centre, University of Sydney,
Australia, which is a member of the Australian Photonics Cooperative Research
Centre.
Abstract:
Second harmonic generation from coupled surface plasmon
resonances of Au@SiO2 nanoparticles self-assembled on glass
Tomokatsu Hayakawa, Yoshitaka Usui, Yang Yong, and
Masayuki Nogami
Department of Materials Science and Engineering, Nagoya
Institute of Technology, Gokiso, Showa, Nagoya 466-8555, Japan, TEl/FAX:
+81-52-735-5110, E-mail: hayatomo@nitech.ac.jp
Abstract:
Design of Photonic Crystal Fibers for
Optical Parametric Amplification
Gabriele Bolognini
National Excellence Center for Photonic Networks, Scuola Superiore
Sant'Anna, 56127 Pisa, Italy E-mail: gabriele.boloanini@cnit.it, tel.: +39 050 9719
013.
Abstract:
Extruded tellurite photonic crystal fibre
A.Wang, V.V.Ravi Kanth Kumar, Alan K.George, J.C.Knight, P.St.J.Russell
Optoelectronics Group, Department of Physics, University
of Bath, BA2 7AY, U.K. Tel: +44(0) 1225-385007, Fax: +44(0) 1225-386110, ernail:
pypaw@bath.ac.uk
Abstract:
Electron Paramagnetic Resonance and optical absorption
characterization of E'ă centers in silica
G.Buscarino, S.Agnello, R.Boscaino, F.M.Gelardi
INFM and Department of Physical and Astronomical
Sciences, University of Palermo, Via Archirafi 36, 90123 Palermo, Italy Tel:
+39 0916234218; fax: +39 0916162461; e-mail: buscarin@fisica.unipa.it
Abstract:
Photo-conversion of oxygen deficient Ge-related
canters in natural silica
F.Messina, M.Cannas, R.Boscaino
*INFM and Dipartimento di Scienze Fisiche ed Astronomiche
dell'Universitŕ di Palermo, via Archirafi 36, I-90123 Palermo, Italy
Abstract:
Influence of the modulation instability on the
formation of supercontinuum in tapered and cobweb fibres
Serguei M.Kobtsev, Serguei V.Smirnov
Laboratory of Laser Systems, Novosibirsk State University,
Russia, 630090 Novosibirsk, Pirogova Street, 2. E-mail: kobtsev@lab.nsu.ru,
Telephone / fax : +7 3832 397224
Abstract:
Changes in etch rate due to hydrogen loading and
UV-irradiation in phosphorus-doped fibers
F.Dürr, G.Kulik, H.G.Limberger, R.P.Salathé
Institute of Applied Optics, Swiss Federal Institute of
Technology, CH-1015 Lausanne, Switzerland Phone: +41-21-693 51 93, fax:
+41-21-693 37 01, e-mail: florian.duerr@epfl.ch
S.L.Semjonov
Fiber Optics Research Center at the General Institute of
the Russian Academy of Science, 38 Vavilov Street, 117942 Moscow, Russia. Phone: 7 (095)
125-0566, fax: 7 (095) 135-8139, e-mail: sls@fo.gpi.ru
Abstract:
Raman fibre 1 μm => 2 μm converter
A.E.Rakitin, I.A.Bufetov, V.M.Mashinsky, O.I.Medvedkov, A.V.Shubin,
S.A.Vasiliev, E.M.Dianov
Fibre Optics Research Center at General Physics Institute
of the Russian Academy of Sciences, 38 Vavilov Str., 119991 Moscow, Russia rakitin@fo.gpi.ru,
iabuf@fo.gpi.ru, vrnrn@fa.gpi.ru, shubin@fa.gpi.ru, sav@fo.gpi.ru, dianov@gpi.ru
Abstract:
Full vectorial modal solutions for photonic crystal fibres
by use of the finite element method
B.M.Azizur Rahman, A.K.M.Saiful Kabir, M.Irfan Ahmed, Muttukrishnan
Rajarajan, and Kenneth T.V.Grattan
School of Engineering and Mathematical Sciences, City
University Northampton Square, London EClV OHB Tel: +44-20-7040-8123 Fax:
+44-20-7040-8568 Email: B.M.A.Rahman@city.ac.uk
Abstract:
Coherent octave-spanning supercontinuum generation in
a SF6-fiber for a frequency comb around 1560 nm
Holger Hundertmark, Dieter Wandt, Carsten Fallnich
Laser Zentrurn Hannover e.V., Hollerithallee 8, 30419 Hannover,
Germany Tel: +49-511-2788-264: Fax: +49-511-2788-100; Email: hu@lzh.de
V.V.Ravi Kanth Kumar, A.K.George, J.C.Knight, P.St.J.Russell
Optoelectronics Group, Department of Physics, University
of Bath, Claverton Down, Bath, BA2 7AY, U.K. Email: pysrkk@bath.ac.uk
Nits Haverkamp, Harald R.Telle
Physikalisch-Technische Bundesanstalt, Bundesallee
100,381 16 Braunschweig, Germany Email: Harald.Telle@ptb.de
Abstract:
Cascaded nonlinearity and two-color solitons in
photonic band-gap fibres filled with a Raman active gas
Dmitry V.Skryabin, Fabio Biancalana, Bavid M.Bird, Fetah Benabid
Department of Physics, Univemity of Bath, Claverton Down,
Bath, BA2 7AY, U.K.
Abstract:
Magnetic Domain Imaging Using Linear and Non-Linear
Scanning Near-Field Optical Microscopy
Wayne Dickson, Satoshi Takahashi and Anatoly V.Zayats
School of Mathematics and Physics, The Queen's University
Belfast, Belfast, BE' INN, UK Tel: +44 2890973511; Fax: +44 2890973110; E-mail:
w.dickson@qub.ac.uk
Abstract:
Radioluminescence and luminescence kinetics of
fluoride glasses.
Kurdvavko P.V., Stepanov V.A., Stepanov P.A.
249031 Kaluga region, Obninsk, Bondarenko I, IPPE tel:
8[08439) 9-83-82, fax : 8 (095) 230-23-26, e-mail: pkurd@mail.ru
Abstract:
Quasi-CW purely rotational stimulated Raman scattering
in H2-filled hollow-core photonic crystal fibre
G.Antonopoulos, F.Benabid, J.C.Knight and P.St.J.Russell
Department of Physics, University of Bath, Claverton
Down, Bath, BA2 7AY U.K. pypga@bath.ac.uk
Abstract:
Engineering the dispersion of tapered fibres for supercontinuum
generation
C.M.B.Cordeiro, W.J.Wadsworth, T.A.Birks and P.St.J.Russell
Optoelectronics Group, Department of Physics, University
of Bath, BA2 7AY, Bath, England
Abstract:
Room temperature stability of the second order
susceptibility induced in thermally poled silica glasses
Alexandre Kudlinski, Yves Quiquempois, Gilbert Martinelli
University des Sciences et Technologies de Lille, Laboratoire
de Physique des Lasers Atornes et Molecules, Centre d'Etude et de Recherche sur
les Lasers et Applications UFR de Physique, bâtiment P5, 59655 Villeneuve d'Ascq,
France Email: alexandre.kudlinski@phlam.univ-lille1.fr
Abstract:
Cross comparison between theoretical and experimental
modal field patterns in a doped-core microstructured fiber
R.Parmentier, M.C.Phan Huy, G.Laffont, V.Dewynter-Marty
and P.Ferdinand
CEA-DRT-LIST-DETECS-SYSSC-LMO, Centre de Saclay, 91191
Gif-sur-Yvette Cedex, FRANCE Tel.:+33 1 69 08 29 38 Fax:+33 1 69 08 83 95
guillaume.laffont@cea.fr
P.Roy, J-M.Blondy and D.Pagnoux
IRCOM/OGI, UMR-CNRS 6615,123 avenue Albert Thomas, 87060 Limoges
Cedex, FRANCE Tel.:+33 5 55 45 72 69 Fax:+33 5 55 45 72 53 pagnoux@ircom.unilim.fr
B.Dussardier
LPMC/FOA, UMR-CNRS 6622, Universite de Nice Sophia-Antipolis,
Pan: Valrose, 06108 Nice Cedex 2, FRANCE Tel.:+33 4 92 07 67 48 Fax:+33 4 92 07
67 54 bernard.dussardier@unice.fr
Abstract:
Photosensitivity of H-free Phosphosilicate Fibers
Yu.W.Larionov, A.A.Rybaltovsky, E.8.Ksyukova, W.O.Sokolov,
V.G.Plotnichenko.
Fiber Optics Research Center at the General Physics
Institute, Russian Academy of Sciences 38 Vavilov Street, 11 9991 Moscow,
Russia Tel.: 7(095)132 8207, Fax: 7(095)135 8139, E-mail : luv@fo.gpi.ac.ru
Abstract:
Giant pulses generation with all-fibre Raman laser
G.Ravet, A.A.Fotiadi*, M.Blondel, P.Megret
Service d'Electromagnetisme et de telecommunications, Faculté
polytechnique de Mons, 31 bld Dolez, 7000 Mons, Belgium Tel:+3265374 144, fax:
+3265374 199, e-mail: ravetg@telecom.fpms.ac.be
Abstract:
Tapered dual-core airclad fiber for generation of
polarized supercontinuum
Sergei Kobtsev, Sergei Kukarin, and Nikolai Fateev
Laser Systems Laboratory, Novosibirsk State University; Novosibirsk
630090, Russia + 7 (3832) 39 7224, kobtsev@lab.nsu.ru
Vladimir Mezentsev and Sergei Turitsyn
Photonics Research Group, Aston Universrty, Birmingham 84
7ET, United Kingdom +44 (121) 359 3611, v.mezentsev@aston.ac.uk
Abstract:
Radiation and Scattering of Linear Waves and Solitons
in Photonic Crystal Fibers
D.V.Skryabin, A.V.Yulin, F.Biancalana, F.Luan, J.C.Knight,
N.Joly and P.St.J.Russell
Department of Physics, University of Bath, Bath BA2 7AY, UK
email: d.v.skryabin@bath.ac.uk
Abstract:
Output spectra and longitudinal mode structure of the
Raman fiber laser
S.A.Babin, D.V.Churkin, S.I.Kablukov
Institute of Automation and Electrometry, Siberian
Branch, Russian Academy of Sciences, 1 Ac. Koptug Ave., Novosibirsk 630090,
Russia Tel/fax: +7 (3832) 341832 e-mail: dimkins@yandex.ru
Abstract:
FBG-based asymmetrical off-centred VSB filters for
transmission with 0.8 bit/s/Hz spectral efficiency
E.G.Turitsyna, A.Gillooly, V.K.Mezentsev, and S.K.Turitsyn
Photonics Research Group, School of Engineering and
Applied Science, Aston University, Birmingham B4 7ET, UK. Tel:+441213593611,
ext 4952, Fax:: +44 1213590156, Email: e.a.turitsyna@aston.ac.uk
Abstract:
Polarization mode dispersion reduction in spun silica
holey fibres
M.Fuochi1, J.R.Hayes, M.N.Petrovich, J.C.Baggett,
T.M.Monro, D.J.Richardson
0ptoelectronics Research Centre, University of Southampton,
Southampton SO17 1BJ, UK
Abstract:
Femtosecond laser assisted rewriting 3D data storage
in composite glass with Ag nanoparticles
A.Podlipensky, A.Abdolvand, G.Seifert, M.Graener
Martin-Luther-University Halle- Wittenberg, Physics
department, Optics, HoherWeg 8, 06099 Halle, Germany Tel:+49 345 55253 15, Fax:+49
345 5527221, e-mail: podlipensky@physik.uni-halle.de
Abstract:
Extruded small-core bismuth oxide glass holey fibres
P.Petropoulos, H.Ebendorff-Heidepriem, S.Azimakis, R.C.Moore,
K.Frampton, F.Koizumi, T.M.Monro, D.J.Richardson
Optoelectronics Research Centre, University of Southampton,
Southampton SO17 1BJ, United Kingdom. pp@orc.soton.ac.uk
Abstract:
Nonlinear optics in photonic crystal fibers with
negative-dispersion slope
N.Y.Joly1, A.Efimov2, F.G.Ornenetto3,
A.J.Taylor2, J.C.Knight1 and P.St.J.Russell1
1. Optoelectronics group, Dept. of Physics, University of
Bath, BA2 7AY, UK Tel+44 1225 384532, Fax: +44 1225 386110 e-mail:
pvsnai@bath.ac.uk
Abstract:
Cascaded nonlinearity and two-color solitons in
photonic band-gap fibres filled with a Raman active gas
F.Biancalana, D.V.Skryabin, D.M.Bird and F.Benabid
Department of Physics, University of Bath, Bath BA2 7AY,
UK
Abstract:
Visible broadband continuum generation in nano-scale
silica-air waveguides
S.G.Leon-Saval, T.A.Birks, W.J.Wadsworth and P.St.J.Russell
Department of Physics, University of Bath, Claverton
Down, Bath BA2 7AY, United Kingdom. Email: pypsgl@bath.ac.uk
M.W.Mason
BlazePhotonics Ltd, University of Bath Campus, Claverton
Down, Bath BA2 7AY, United Kingdom.
Abstract:
Ultraviolet-induced absorption during very short
continuous exposure in Ge-doped optical fiber
K.Medjahdi, F.Goutaland, A.Boukenter and Y.Ouerdane
Laboratoire Traitement du Signal et Instrumentation, UMR
5516 CNRS Université de Saint-Etienne, 10 rue Barrouin, Bât. F 42000
Saint-Etienne, France Tel: +33 (0)4 77 91 58 14 Fax: +33 (0)4 77 91 57 81
e-mail: kader.medjahdi@univ-st-etienne.fr
Abstract:
Towards metallic microstructuring in nanocomposite
glass
A.Abdolvand1, A Bodlipensky1, G.Seifert1,
H.Graener1, O.Deparis2, P.G.Kazansky3
1. Optics Group, Physics Department,
Martin-Luther-University, Halle D-06099, Germany e-mail: abdolvand@physik.uni-halle.de;
Tel.: +49 (0)345 5525315; Fax: +49 (0)345 5527221
Abstract:
Effects of interface modes on hollow core photonic
crystal fibres
G.Humbert, J.C.Knight, P.St.J.Russell
Department of Physics, University of Bath, Claverton
Down, Bath, BA2 7AY United Kingdom Tel: +44 1225 384368, Fax: +44 1225 386110, email: pysgh@bath.ac.uk
Abstract:
Genetic algorithm: a solution to design photonic
crystal fibers
Emmanuel Kerrinckx, Laurent Bigot, Geraud Bouwmans, Marc Douay,
Yves Quiquempois
Laboratoire de Physique des Lasers, Atomes et Molecules, UMR
8523 Institut de Recherche sur les Composants logiciels et matériels pour l'Information
et les Communications Avancées, Université de Lille I - UFR de Physique, Bâtiment
P5, 59655 Villeneuve d'Ascq Cedex, France Tel: 33.3 20.43.48.14, Fax 33.3
20.33.70.20 Emmanuel.Kerrinckx@phlam.univ-lille1.fr
Abstract:
Spatial manipulation of the valence state of
rare-earth ions in macroporous media prepared by a sol-gel method
Shunsuke Murai, Koji Fujita, Kazuki Nakanishi, and
Kazuyuki Hirao
Department of Material Chemistry, Graduate School of
Engineering, Kyoto University, Kyotodaigaku-katsura, Nishikyo-ku, Kyoto 61
5-8510, Japan Tel/fax: +81-75-383-2413/2410, e-mail: murai@collonl.kuic.kyoto-u.ac.jp
Abstract:
Fabrication of fibre Bragg gratings with 267 nm ferntosecond
radiation
K.A.Zagorulko, P.G.Kryukov, Yu.V.Larionov, A.A.Rybaltovsky,
E.M.Dianov
Fibre Optics research Center at the A M Prokhorov General
Physics Institute of the Russian Academy of Sciences, 38 Vavilov Street, Moscow
119991 Russia Tel: 7 (095) 135-7530, Fax: 7 (095) 135-8139, E-mail: zagorulko@fo.gpi.ru
Abstract:
Optical properties of nano-hole arrays in thin
metallic films
Jill Elliott, Igor I.Smolyaninov*, Satoshi Takahashi, Anatoly
V.Zayats
School of Mathematics and Physics, Queens University
Belfast, Belfast BT7 1NN, UK Tel: 02890 973941, Fax: 028990 9731 10, Email:
j.elliott@qub.ac.uk
Abstract:
Initial and radiation-induced loss in holey optical
fibres with silica core
A.F.Kosolapov, I.K.Nikolin, A.L.Tomashuk, S.L.Semjonov, M.O.Zabezhailov
Fibre Optics research Center at the A.M.Prokhorov General
Physics Institute of the Russian Academy of Sciences, 38 Vavilov Street, Moscow
119991 Russia
Abstract:
Large core holey fibers with a few air channels in
cladding - modelling and experimental investigation of the modal properties
V.P.Minkowich and A.V.Kir'yanow
Centro de Investigaciones en Optica, Loma del Bosque.
#115, Col. Lomas del Campestre, Leon 37150, Gto, Mexico Tel: (52) (477)
717-5823, Fax: (52) (477) 7175000, Email: vladimir@cio.mx
A.B.Sotsky and I.B.Sotskaya
Institute of Applied Optics of National Academy of
Sciences of Belarus, B.-Biruli Str., #11, Mogilev 212793, Belarus
Abstract:
Lasing in hexagonal molecular sieve waveguide
resonators
U.Förster
Institut für Angewandte Physik, Technische Universitaet
Darmstadt, Germany
Abstract:
Closer examination of the symbiotic system can lead to a
better understanding of the optical conditions for the lasing process as well
as the morphological requirement for the crystal to function as a laser. Several
aspects of the compound are examined for a better understanding of the system:
mode existence, coupling of modes as well as different resonators, photostability
of the dyes, and arrangement of the dye guests inside the host, which
introduces new symmetries leading e.g. to pyroelectricitic properties of the
composite.
I will describe photosensitivity in glasses with
specificity for silica based ones. The term photosensitivity means firstly that
at least the first step of mechanism leading to some changes in physical
properties, is a one or multiphoton absorption, secondly that the lifetimes of
these changes are much longer than the one of the usual luminescence. From
that, there are a lot of various effects depending on the chemical composition
of the glass, but also, for a given glass, depending on the laser wavelength,
power density or type (CW pulsed). I will describe a classification with some examples.
Lastly, I will show complex mechanisms combining several effects.
Residual stresses in optical fibre contribute to the
overall refractive index distribution via the photoelastic effect. Absorption
of laser light triggers stress changes and leads to refractive index modifications.
This process may relax residual stresses in the glass network and thus explain
the observed photosensitivity in optical fibres. However, the 'stress relief
model' proposed by M.Sceats et al. failed to explain photosensitivity.
Nevertheless, it triggered the investigation of light induced stress changes in
optical fibres. They depend on core dopants, fibre drawing, pre-sensitization,
and irradiation conditions. The photoelastic contribution can be correlated to
total index changes. Thus conclusions about other dominant mechanisms, like
compaction or colour centre changes may be drawn. Stress measurements in
optical fibre and the role of light induced photoelastic index changes are
presented.
It is no understatement to claim, that the Bragg grating
[1,2] is the most significant fibre-optic invention since the erbium-doped
fibre amplifier (EDFA). Unquestionably, it is the most versatile optical-fibre
filter that exists and it has, hand-in-hand with the EDFA, facilitated dense
wavelength division multiplexing (DWDM) in telecommunications, providing better
processing of densely packed optical frequencies and easily out-performing any
other available filter-technology. Further studies into the design, fabrication
and applications of fibre Bragg gratings therefore are of major interest for future
communication-systems, besides a diverse range of other applications including
sensing, and short pulse fibre lasers. A Bragg grating is a periodic or
almost-periodic structure, consisting of a variation of for example the
refractive index with a typical period of ~0.5μm along the length of a waveguide
and is typically formed within this waveguide using side-exposure to intense
ultra-violet light [2]. By phase-matching the individual small reflections
generated by the high-low, low-high index regions of difference ~10-4
along the waveguide, strong overall reflection of light incident on the grating
is obtained within a well-defined spectral pass-band. Therefore, a Bragg
grating can act as a band-rejection filter passing the wavelengths that are not
in resonance with the grating and strongly reflecting wavelengths that satisfy
the Bragg condition. The technology of Bragg gratings has matured significantly
over the past years and with the recent advances in manufacturing capabilities
of these obviously there will develop a demand for filters of even higher
complexity to perform very specific filtering tasks. Currently it is often the
imagination that sets the limits for what can be achieved experimentally. Of
particular practical significance is the possibility to alter and control both
the amplitude and phase of light reflected and/or transmitted through a
grating. This possibility has been exploited in the past for a range of optical
signal processing function including, for example, static chromatic dispersion
compensation in optical fibre links [3], and the design and fabrication of
Bragg grating filters for complex phase and amplitude coding applications
similar to those used in microwave code-division multiple access (CDMA)
communication systems [4]. These and many other recent new applications [5] of
fibre Bragg gratings together with an overview of Bragg grating design-and
fabrication-techniques will be taught in this lecture.
[1] K.O.Hill et al., Appl. Phys. Lett., 32, p.647, 1978.
[2] G.Meltz et al., Optics Lett., 14, p.823, 1989.
[3] D.Garthe et al., IEE Electron. Lett, 30, p.2159,
1994.
[4] P.C.Teh et al., in proceedings to OFC'OO, PD9, 2000.
[5] M.Ibsen and R.Feced, Optics Lett., 28, p.980, 2003.
This lecture will focus on the applications of fibre
grating devices mainly in sensing but also briefly in telecommunications. For
sensing applications it is necessary to determine the measurand induced shift
in Bragg wavelength. Many techniques for carrying this out have been
demonstrated in research laboratories and there are now several commercial
systems available, some of which will be reviewed. The lecture will cover
applications of grating sensors in the fields of civil engineering, aerospace
and medicine. Long period gratings will be introduced and their properties
contrasted with those of Bragg gratings. Applications making use of some of the
unique features of long period gratings will be presented.
Glass materials used in optical fibres and planar
waveguides do not exhibit second order optical nonlinearity. However, through
poling it is possible to record a strong nearly permanent electric field in the
glass, thus breaking the intrinsic symmetry and inducing nonlinear phenomena,
such as frequency doubling and the linear electrooptic (Pockels) effect. The
nonlinearity induced in poled fibres and planar waveguides is sufficient to
find practical applications in switches, modulators and frequency converters.
In this lecture, the technology and some of the basic mechanisms of poling will
be presented.
The presentation concerns the various techniques used for
inscriptions of components using glass photosensitivity. Gratings inscriptions
(slanted, apodized, chirped) and UV patterning will be exposed for components
written in fibers and/or planar waveguides. Concatenations, reductions of
polarisation dispersion losses and polarisation modal dispersion will be
exposed for gain equalisation in optical amplifiers. Presentations will be also
exposed within the framework of the European contract Platon (Planar
Technologies for Optical Networks). The aim of PLATON project is to study,
develop and assess photosensitive planar technology in a system context,
through key devices for future optical metropolitan networks.
The main tendency of modern electronics including quantum
electronics is miniaturization. Ultrashort-pulse lasers and fibre optics are
examples of this tendency. The development of ultrashort-pulse lasers resulted
in the fabrication of compact systems capable of emitting pulses of duration as
short as a few cycles of a light wave with extremely high peak powers. A unique
feature of femtosecond lasers is that they can generate radiation whose
temporal coherency can be varied by 15 orders of magnitude. In fact, if a
single pulse is selected from a continuous train of pulses, the temporal coherence
of radiation cannot be grater than the pulse duration. At the same time, the
spectrum of the train consists of an equidistant comb of narrow, as small as a
few hertz, lines. This feature allows the use of femtosecond lasers both in
optical coherent tomography, where an ultimately low temporal coherence is
required, and in high-precision optical-frequency metrology, which requires
extremely narrow laser lines. The union of femtosecond lasers and fibre optics
is rather fruitful. Special fibres, for example, of the photonic-crystal type,
provide a considerable increase in the comb spectrum until more than an octave,
which is very important for metrological applications. The Er- and Yb-doped femtosecond
fibre lasers are more compact and less expensive than Ti:sapphire lasers
(working horse of femtosecond science and technology). Femtosecond laser pulses
are successfully used for manufacturing important elements of fibre optics. The
fabrication of long-period and Bragg fibre gratings and writing of waveguide
structures in transparent materials with the help of femtosecond pulses were
demonstrated. The results of studies of femtosecond fibre lasers and
fabrication of fibre gratings with help of femtosecond pulses performed at FORC
RAS are presented.
Optical glass fibres and waveguides dominate optical
communications. The development of linear electrooptic modulators/switches and
parametric frequency converters directly integrated into optical glass waveguide
structures technologically is very attractive. However such components require
a second-order optical nonlinearity - a χ(2)
which is normally absent in glass owing to its inversion symmetry. Thus, when
self-organized frequency doubling was first discovered wide-ranging studies ensued
into the mechanism and properties of this unexpected phenomenon. The mystery of
self-organized χ(2)
gratings was finally solved on the basis of a new physical phenomenon - the
coherent photogalvanic effect, consisting in quantum interference between light
fields at two different frequencies, ω and 2ω, which excites a phase
dependent current (coherent photocurrent). Coherent photocurrent creates
quasi-phase matching χ(2)
gratings. Moreover in the experiments on electric-field second harmonic
generation in optical fibres the first evidence of phase dependent modulation
of a total cross-section of ionization due to quantum interference (coherent
photoconductivity) in solid state materials has been obtained [1]. Another
interesting field demonstrating unusual light-matter interactions and
properties of materials is modification of index of refraction and direct
writing of photonic structures by. ultrashort light pulses in glass. A critical
advantage of using femtosecond pulses relative to longer pulses for optical
writing and data storage is that such pulses can rapidly and precisely deposit
energy in solids. This is the principle of femtosecond photosensitivity and 3D
direct writing of photonic structures ranging from 3D waveguides to embedded Fresnel
zone plates. This research has led to demonstration of new phenomena -
anomalous anisotropic light scattering and form birefringence in glass [2]. The
anisotropic phenomena have been interpreted in terms of self-induced index nano-gratings
in glass and self-organized form birefringence, which is a new manifestation of
self-organization under intense irradiation. The observed self-organized
periodic structures are the smallest (20 nm width) and the strongest (-0.2
index change) ever created by light in transparent materials. Moreover these
are the first gratings created by light-matter (electron plasma) interference [3].
In the talk I review properties and potential applications of glass and optical
fibres modified by strong fields and related new phenomena.
[1] Phys. Rev. Let. 78, 2956 (1997)
[2] Phys. Rev. Lett. 82, 2199 (1999)
[3] Phys. Rev. Lett. 91, 247405 (2003)
The linear and nonlinear optical properties of nano-structured
materials on the basis of glass can be designed within a very broad range of
parameters to meet the needs of optical and optoelectronic applications. In
particular glass containing metal or semiconductor nanoparticles can be
engineered by modifying shape and spatial distribution of the nanoparticles
using ultrashort laser pulses. In this lecture, the physics of the
laser-induced particle modification and the optical characteristics of the structures
produced will be discussed as well as the potential applications of this laser
engineering of the nanostructure of composite glasses.
The growing applications of lasers in various fields of
contemporary technology, in medicine, for scientific research demand new laser
frequencies in UV, visible and IR regions. The efficiency, compactness,
flexibility in wavelength selection and high quality of the output beam of
lasers are essential for many applications. Raman fiber lasers, a triumphal
advent of which is connected with striking success in fiber optics technology
meet these requirements. The lecture will focus on recent results in the
development of new Raman fibers and in the creation of the family of Raman fiber
lasers with practically any wavelength in the spectral region of 1-2 μm
and beyond.
In this lecture we first consider fundamental principles
and effects of nonlinear fibre optics and in particular effect of nonlinear
pulse propagation in optical fibres. Then a detailed description of ultrashort
fibre laser will be given with special emphasis on properties and features of soliton
fibre lasers operating in a wide spectral range. The second part of the lecture
is focused on approaches to generate high average power and ultra-high peak
power in all-fibre systems. Particular attention will be paid to novel
technologies to maintain integrity and high fidelity of ultrashort pulses and
potential applications of such systems.
In this lecture, the physical processes involved in the
generation and optimisation of extreme-ultraviolet and soft x-ray light though
the process of high-order harmonic generation will be discussed. Using concepts
from visible wavelength photonics, it is now possible to extend nonlinear
optics well into the x-ray region of the spectrum. We show that by manipulating
the dynamics of this process using optimised waveguide structures and pulse
shapes, we can control the energy of the emitted photons, as well as
phase-matching the conversion process. Use of optimised structures can also improve
the spatial and temporal coherence of the light. Finally, applications of
ultra-fast x-rays in monitoring molecular dynamics on surfaces will also be
discussed.
[1] Nature 406, 164 (2000)
[2] Science 297, 376 (2002)
[3] Science 302, 95 (2003)
Coding data bits in the phase or polarisation state of
single photons allows us to exploit wave particle duality for novel computing
and communication protocols. The first practical applications are the fibre and
free-space quantum cryptography apparatus used for secure exchange of keys [1,2].
Further developments such as quantum relays and other few qubit applications
require that pairs of qubits interact. To avoid the inevitably weak non-linear
interactions between photons conditional linear optics logic has been developed
to demonstrate CNOT operation albeit with limited efficiency [3,4]. Optical
quantum logic schemes thus require high efficiency sources and detectors of
single photons. However, in the future we would also want non-linearity at the
single photon level. These components in the quantum logic toolbox could be
realised by exploiting wavelength scale engineering of optical structures. The
strong modification of mode density within periodic dielectric structures can
drastically modify spontaneous emission from two-level systems. This can
manifest as changes in spectral content, changes in lifetime and in low power
saturation (non-linear) effects. Suitable two-level systems could be colour
centres in crystals, quantum dots in semiconductors and transition metals in glassy
materials. Of interest to the field of quantum information are single two-
level systems coupled to a strong resonant mode. Such a system could form the
basis of a single photon source, a single photon detector and single photon
non-linear element. This talk will explore these ideas in the context of
micro-structured materials.
[1] N.Gisin, G.Ribordy, W.Tittel and H.Zbinden Rev. Mod. Phys.
74, 145 (2002).
[2] C.Kurtsiefer et al, Nature 419, 450 (2002).
[3] J.G.Rarity, Roy. Soc. Phil. Trans. 361, 2003, 1507-18
[4] J.L.O'Brien et al, Nature 426, 264 (2003).
The classical macroscopic theory of near-field optical
interactions is briefly reviewed paying particular attention to the role of
evanescent fields. Starting from the electromagnetic field of a point dipole multiple
near-field scattering is discussed. Studies of mescoscopic objects - such as quantum
dots, wires and wells - necessitate that the near-field particle-particle
interaction is treated on the basis of quantum mechanics. In the final part of
the lecture I discuss in a field-unquantized setting the quantum approach to
near-field optics starting from a description of the interaction between two atoms
(molecules) in near-field contact. Near-field optics is of importance not only
for applied optics, but also in theoretical physics because it helps us to
unify the description of certain basic physical phenomena usually studied
separately. Starting from near-field optical concepts I discuss (i) the space-time
generation of single-photon wave packets in first quantization, (ii) the
spatial resolution problem in optics, (iii) photon tunnelling, (iii) photon
embryos, and (iv) causality.
This Lecture will present a systems analysis for a
Quantum Factorisation Engine built in Si-Ge technology. This will be a review
of the types of devices and system architectures that will be needed in order
to make a quantum information processor in the Ge-Si material system. Attention
will be paid to the required elementary operations; single spin measurement,
single spin rotation, and two spin interaction. The UCLA group has recently
measured a single electron spin inside a conventional Silicon integrated
circuit. The fidelity requirement of the gate operations for quantum error
correction represents the principal technical challenge, among many others
Quantum Technology deals small systems which can be
isolated long enough to be useful as quantum systems. One example is the ultra
cold neutral atom. An overview of the field of matter wave optics will be
presented. We will then discuss the combination with integrated photonics on
the atom chip, as a way of realizing quantum technology, through trapping, guiding,
manipulating and measuring atoms.
The recent developments in scanning near-field optical
microscopy (SNOM) have provided the possibility to visualise optical processes
on the subwavelength scales with an optical resolution inaccessible by
traditional far-field approaches which are limited by diffraction effects. This
has opened up a new research field of nano-optics concerned with studies and
applications of nano-scale optical effects and nanoscopic light sources. In
this talk we will discuss the principles of nano-optics and scanning near-field
optical microscopy and their applications in nano-photonics. After reviewing experimental
approaches to near-field optical studies, we will focus on the examples of
nonlinear nano-optics and surface plasmon photonics. A conventional
aperture-based SNOM makes use of a small aperture which is scanned at a fixed
distance in near-field proximity above the sample surface. In an apertureless SNOM,
a nanoscopic scatterer is employed to probe the near-field distribution. Using
a SNOM one can image, simultaneously, the surface topography and the optical
field above the surface that allows correlation of the observed optical
response to specific surface features. Nano-local absorption, reflection and
fluorescence have been' successfully studied with SNOM. Nonlinear approaches to
SNOM, particularly second-harmonic generation, have significantly improved
optical resolution of the technique due to the electromagnetic field
enhancement effects at the probe tip. Associated field confinement provides an
opportunity to achieve strongly localised light sources. Near-field
second-harmonic generation combines the extremely high surface sensitivity of second-harmonic
generation with the high spatial resolution of SNOM and can lead to the development
of new tools for imaging, local optical studies and modification of materials
as well as novel nonlinear photonic devices on the subwavelength-scale. Only
with near-field microscopy the direct studies of surface plasmons whose
electromagnetic field is confined to the surface, have become possible. In turn
surface plasmon effects facilitate nonlinear optical processes due to the associated
with them field enhancement. It is the surface polaritons that determine the
majority of linear and non-linear optical properties of metallic
nanostructures. Surface plasmon polaritons are emerging as a new information
carrier that enables manipulation and control of optical signals in a subwavelength
photonic circuitry. Numerous applications can be envisaged in optical
information processing and optical communications.
1. "Nano-optics and near-field microscopy," D.Richards
and A.Zayats, Eds., Phil. Trans. Royal Soc. A, vol. 362, 2004, pp. 699-919.
2. A.V.Zayats and I.I.Smolyaninov, "Near-field
second-harmonic generation," Phil. Trans. Royal Soc. A, vol. 362, 2004,
pp. 843460.
3. A.V.Zayats and I.I.Smolyaninov, "Near-field
photonics: surface plasmon polaritons and localised surface plasmons," J.
Opt. A: Pure Appl. Opt., vol. 5, 2003, pp. 516-550.
Optical forces can dramatically influence the kinetic
motion of objects ranging from the microscopic or cellular size right down to
the atomic scale. In this lecture I will discuss the optical forces and show they
may be used to tweeze particles and also cool atoms and guide both cold atoms
and quantum degenerate gases. An overview of the state-of the art on optical
micromanipulation will be given showing new areas of science that are emerging
including the use of new and multiple beam shapes, optical sorting and optical
transport including guiding along photonic crystal fibres. At the atomic scale I
will give an overview of atom guiding and manipulation including applications
for atom lithography and nano-positioning of atomic ensembles including
Bose-Einstein condensates.
Supercontinuum generation in photonic crystal fibre has
now been reported under many different experimental conditions. This paper
reviews supercontinuum generation over the full range of experimentally-reported
parameters from the nanosecond to the femtosecond regime, and discusses the
dominant frequency conversion mechanisms in each case. Despite apparent visual
similarities between supercontinua generated under different conditions, it is
shown that the intensity, phase and stability of the supercontinua can vary
significantly. This paper will provide an overview of the underlying spectral
broadening mechanisms and supercontinuum properties that should allow the optimization
of supercontinuum sources tailored to particular application needs.
Materials with μ < 0 and ε < 0 were
christened 'left handed' by Veselago because the wave vector and Poynting
vector lie in opposite directions. It was later suggested that they could also
be described by a negative refractive index, n < 0, an although this was
disputed by some there are now several reliable experiments and computer
simulations which show that this is indeed the case. In this talk I shall
describe how the negative attribute goes even deeper. Regions of space with n
< 0 can be thought of as optically cancelling or negating neighbouring
positive regions. The simplest instance is a slab of n = -1 material of
thickness d which cancels an equivalent thickness of vacuum and therefore acts
as a lens: objects are brought into focus as an image a distance 2d along the
normal to the slab. Other more complex instances of negative space will be
discussed in the talk.
2. Politecnico di Torino, Dipartimento di Scienza dei Materiali
e Ingeneria Chimica, Corso Duca degli Abruzzi, 24 10129 Torino, Italy Tel.: ++49 40 42878 3437, Fax: ++49 40 42878 2860, Knappe@tu-harburg.de
In this paper, the fabrication of waveguides by direct
ultraviolet (UV) writing into a bulk tin-doped multicomponent silicate glass is
presented. Refractive index increases in non-hydrogen-loaded samples of up to 5
× 10−3 were measured.
We are interested in the study of linear defects induced
in silica by femtosecond laser irradiation. Its cross-section, revealed by
cleaving the silica sample, presents a granular region at the input and a
discontinuous tail.
Femtosecond direct written waveguides in bismuthate
glasses are reported. This is the first demonstration of direct written guiding
channels in bismuthate glass which show an index of refractive change as high
as 3 x 10-3
We report novel results on the stability of femtosecond
direct written structures: a silica sample previously irradiated with ultrashort
pulses was annealed at increasing temperatures till 1400o C where
it crystallized. Our results show that the birefringent direct written
structures are stable till a temperature close to the glass transition of
silica. After annealing at a temperature as high as 1100o C the form
birefringence of the structures is still present, proving that the nature of
the laser induced anisotropy is related to a structural change.
We describe schemes for the integration of miniature
optical components onto Atom Chips, for the manipulation and detection of
ultra-cold atoms. Our intention is to build detectors sensitive enough to
accurately detect single atoms. Two approaches . are discussed: simple
fluorescence detection and the use of a resonant cavity. Theory predicts that
cavities with F > 100 should be sufficient to obtain signal to noise ratios
high enough to detect single atoms. The first micro cavities were demonstrated
using mirrors formed by cleaved fiber ends coated with a stick-on dielectric
coating to give F ~100. A more successful approach involves the full
integration of the mirrors and fibers by using Bragg gratings written into the fiber
core: it has been possible to form gap cavities with F ~ 150.
Photosensitivity of different concentrations of antimony
(Sb) codoped alumino-silicate optical fibres are analysed. Bragg gratings with
index modulations of ~3 x 10-4 are reported. The temperature stability
of the gratings is tested and those in higher concentration fibres are found to
be more temperature-resistant.
We describe the design and fabrication of a photonic bandgap
fibre formed using two different glasses. Light is guided in a low-index core
region at wavelengths corresponding to the anti-resonances of the high-index
strands in the fibre cladding.
2. Now at Optoelectronics Research Centre, University of
Southampton, UK Phone:4423-8059-4527; fax: 4423-8059-3 142; e-mail:
asc@orc.soton.ac.uk
The process of hypersensitisation has been demonstrated
with a number of ultra-violet wavelengths, the most recent being with a far-UV
wavelength which is transmissive through the polymer coating. These results are
presented. A further advancement in hypersensitisation through the use of a
low-power UV lamp source is also demonstrated.
Self-assembling fabrication of 2-dimensional gold (Au) nanoparticles
array on aminopropyltrimethoxysilane-terminated glass substrate with various
immersion times into Au sol provided a uniform Au nanoparticles monolayer for
the immersion time of 1 hour and it was revealed that excess immersion times
gave rise to the formation of colloidal domain structures of Au nanoparticles
which, however, induced a second-order nonlinear - polarization generating a
light in double frequency of Nd:YAG laser.
The possibility of achieving broadband, high-gain optical
parametric amplifiers with photonic crystal fibers is investigated. Simulations
point out that it is possible to obtain broadband parametric gain by designing
optimal fiber chromatic second and fourth order dispersion. The influence of fiber
parameters on parametric amplification is discussed.
We report the fabrication and properties of extruded tellurite
photonic crystal fibres (PCFs). The spectral attenuation curve and dispersion
curve of the solid-core tellurite PCFs are provided here. We also describe
possible applications of tellurite PCFs in infra-red supercontinuum generation
and in new forms of hollow-core fibres.
We report an experimental study of the modifications of
Electron Paramagnetic Resonance (EPR) and optical spectra of the E'ă center in
silica induced by room temperature gamma irradiation and by subsequent thermal
treatment. Our data show that the EPR signal of this center changes on increasing
the irradiation dose from an almost axial symmetric line shape to an
orthorhombic one in all but the synthetic wet silica materials, where only the
orthorhombic line shape is found. The changes in EPR signature occurs together
with a red shift of the peak position of the absorption band around 5.8 eV
attributed to the E'ă center. These features suggest the existence of two
different precursors of this center. After thermal treatment the EPR
orthorhombic line shape converts to the axial symmetric one together with a
blue shift in the peak position of the absorption band pointing out a
structural degree of freedom of the E'ă centers.
Conversion processes of Ge-related centers in natural
silica induced by ultraviolet pulsed irradiation with Nd:YAG laser were
investigated. After exposure we observed a reduction of the absorption and
emission bands ascribed to the two fold coordinated Ge (=Ge••) centers
pre-existing in our samples. The bleaching is due to the transformation of =Gem-
in two paramagnetic centers: H(II) by diffusion limited reaction with mobile
hydrogen and Ge(2) by photo-ionization of the precursor =Ge••.
Numerical modelling and study has been conducted of the
specific properties of super-continuum generation in tapered and cobweb fibers
for different pump pulse lengths. For the first time the key role of the
modulation instability in continuum formation has been pointed out both for
long (> 1 ps) and short (~100 fs) pump pulses.
Changes in etch rate due to hydrogen loading and
subsequent UV-irradiation have been observed for phosphorus-doped fiber cores
using an atomic force microscope. The etch rate of the core is found to
decrease after hydrogen loading. UV-irradiation of the hydrogenated fiber
enhances the core etch rate considerably, resulting in a higher etch rate as
compared to the pristine fiber. The change in etch rate does not depend on
pulse fluence, but only on total dose. We attribute the changes in etch rate to
a hydrogen- and radiation-induced modification of color center population.
A Raman fibre laser with the output in the spectral range
beyond 2 μm, converting 1.06 μm radiation into 2.06 μm, has been
demonstrated. Raman fibre converter of 1 μm to 2 μm consists of two successive
Raman lasers based on phosphosilicate and germania-core fibres.
Modal solutions for photonic crystal fibres are presented
by using a rigorous full vectorial finite element-based approach. The effective
indices, spot-sizes, modal hybridness, beat lengths and group velocity
dispersion values are determined for the quasi-TE and TM modes.
We report the octave-broad supercontinuum generation in
an extruded SF6-PCF with an Erbium fiber laser oscillator-amplifier system
around 1560 nm. The oscillator's carrier-envelope-offset-frequency was measured
in a modified f-2f-interferometer and phase-locked to an external reference source
by pump power control.
We report the existence of two-color, temporal
bright-bright solitons supported by cascaded nonlinearity in hollow-core
photonic crystal fibres filled with a Raman active gas and demonstrate the feasibility
of their experimental observation.
High-resolution optical imaging of magnetic domains in
ferromagnetic materials using both linear and non-linear scanning near-field
optical microscopy is discussed. Magnetic domain visualisation is required for
characterisation of the micro-magnetic and magneto-optical properties of novel
magnetic materials and devices for data storage applications.
Radioluminescence (RL) spectra of fluoride glasses (AFG, ZBLAN,
HFG) have been measured under irradiation by 8 MeV . protons. Also luminescence
time of fluoride glasses (HFG and HFG with Ce) have been measured. Luminescence
have been excited by 180 keV electrons.
We report on low-threshold stimulated Raman scattering in
hydrogen-filled hollow-core photonic crystal fibre using low-energy nanosecond
pulses. Different purely rotational Raman transitions have been observed. The
Raman gain dependence on pulse duration over long interaction lengths is also
investigated.
We have experimentally demonstrated engineering the
chromatic dispersion of tapered fibres by immersing them in a fluid. This
enabled us to generate a 1200 nm wide supercontinuum using two tapers, one
immersed in heavy water, pumped by a low-cost diode-pumped Nd:YAG laser with a
pulse width of 0.6ns and an output power of 40mW.
The stability of the χ(2)
susceptibility induced in thermally poled fused silica is investigated. A significant
reduction of the nonlinear width with no modification of the χ(2) susceptibility
magnitude is observed after six months at room temperature.
A scalar version of the localized function method is
implemented and tailored to model doped-core microstructured optical fibers
starting from a microscope picture of the fiber cross section. The program is
evaluated with respect to state-of-the-art modeling results. We report first
data on comparison between calculated and experimentally observed guided modes
of a photosensitive air-silica microstructured fiber.
Photosensitivity of H-free phosphosilicate fibers is
investigated by means of intrafiber interferometer and IR spectrophotometry. Induced
refractive index increases stepwise with dose and its maximum value is
evaluated to be 4.5*10-4. The depth of investigated absorption peaks
changes periodically. Variations in rigidity of glass matrix under UV exposure
can explain the both phenomena.
*also with loffe Physico-Technical Institute of the
Russian Academy of Sciences, 194021 Politekhnicheskaya 26, St. Petersburg, Russia.
We report on the giant pulse operation of a Raman fibre
laser. Pulses with peak power up to 1 kW and duration down to 1 ns were obtained
with a 10km long all-fibre cavity configuration pumped by a 2.4W continuous
wave fibre laser source.
A special dual-core tapered fibre is fabricated for
generation of supercontinuum (SC) with polarization control. A numerical modal
analysis demonstrates a possibility to optimize design of a hybrid 3-in-1
device comprising taper, coupler and polarized SC generator.
We report theoretical and experimental results on several
novel soliton related effects in ultra-small core photonic crystal fibers.
Effects reported rely on peculiar dispersion characteristics, which are not attainable
in telecom fibers.
The shape of output spectrum and its internal structure
arising from multiple longitudinal modes generating in the cascaded cavity of
the two-stage phosphosilicate Raman fiber laser has been studied experimentally
and theoretically. The mode structure has been analyzed using measurements of rf
beat frequency spectra. An adequate analytical model has been developed and
tested experimentally. It describes qualitative behavior and the observed
spectral features for the first and the second Stokes components.
We propose a novel approach to ultra-narrow optical
filtering based on a specially designed slightly asymmetric VSB filter and
fabricate a fibre Bragg gratings with desirable spectral response. A feasibility
of 8x40 Gbit/s DWDM RZ transmission with 0.8 bit/s/Hz spectral efficiency
(without polarization multiplexing) over 1170km of SMF/DCF link without FEC has
been confirmed by numerical modeling.
1. also with Dipartimento di Ingegneria dell'Informazione,
Universita di Parma, 43100 Parma, Italy maf@orc.soton.ac.uk
We report the fabrication of a spun holey optical fibre.
Our experiments show that the complex air/glass transverse structure can be
retained when the preform is spun during the fibre drawing process. Measurements
of differential group delay (DGD) confirm that significant reductions in polarization
mode dispersion (PMD) can be readily achieved using this approach.
3D anisotropic modifications induced in glass with
spherical Ag nanoparticles by multicolor fs laser irradiation was demonstrated
as promising technique for 3D storage by spectral data coding. The
modifications reversible by heating at 600 oC or irradiation by 200
ns laser pulses at 527 nm allow producing of rewriting data storage devices.
We report our progress on the fabrication and
characterisation of highly nonlinear bismuth oxide glass holey fibres. The
measured losses for these fibres were ~3 dB/m at 1.55 μm, and the effective
nonlinearity of the smallest core fibre was as high as 1100 W-1km-1
at the same wavelength.
2. MST-10, MSK764 Los Alamos National Laboratory, Los
Alamos, New-Mexico 87545, USA
3. P-23, MSH803 Los Alamos National Laboratory, Los
Alamos, New-Mexico 87545, USA
We present the nonlinear behavior of large air-filling
fraction photonic crystal fibers specifically designed to have a negative slope
in the vicinity of the zero dispersion point. When ultrashort pulses are
coupled into them, transmission spectra shows unexpected solitonic effect due
to the unusual dispersion curve.
We report the existence of two-color, temporal
bright-bright and dark-bright solitons supported by effective Kerr nonlinearity
in hollow-core photonic crystal fibres filled with a Raman active gas and demonstrate
the feasibility of their experimental observation.
Single-mode supercontinuum spanning (and largely confined
to) the visible spectrum is generated from the nanosecond pulses output of a
532-nm microchip laser, using tens of millimeters of nano-tapered fibres or photonic
crystal fibre cores.
We report ultraviolet (UV)-induced absorption
measurements, in the 360-440 nm spectral region, in germanium (Ge) doped fiber,
H2-loaded or not. This technique allows gives evidence of the photoinduced
mechanisms occurring during very short continuous (cw) UV exposure, contrary to
the usual absorption technique. Our results show that the 4.5 eV absorption
band, extending in the visible region, is responsible for the measured
absorption. We demonstrate that two different defects absorbing at around 4.5 eV
are involved in the two successive reactions, leading to the creation and the partial
of the absorption respectively.
2. Faculté polytechnique de Mons, Service d'Electromagnetisme
et de Telecommunications, Mons B-7000, Belgium
3. Optoelectronics Research Centre, University of Southampton,
Southampton SO17 1BJ, United Kingdom
A novel, easy-to-implement, method to create fine optical
structures in dielectric metal-doped nanocomposite materials is presented. We
believe that our results pave a route towards creation of future optoelectronic
elements based on surface-plasmon integrated circuits.
Hollow-core photonic crystal fibres which guide light in a
air core have very low nonlinearity, unusual dispersion and a high damage
threshold. These unusual properties make them ideally suited to delivery of
laser beams. In specific wavelength ranges, interface or "surface"
modes are guided and interact with core modes. We describe the observed effects
of anti-crossings with interface modes on the fibre properties.
The optimization of the design of photonic crystal fiber
by genetic algorithm is demonstrated for the first time. It is shown how the
combination of this inverse problem approach with a full vectorial finite
element method enables to reach user-defined propagation property. The
definition of a fiber geometry enabling near-zero flat dispersion over a wide
wavelength range is performed as an illustration of the possibilities offered
by this approach.
Sm2+-doped Al2O3-SiO2
glasses with three-dimensionally interconnected macroporous morphology have
been prepared via an alkoxy-derived sol-gel process containing poly (ethylene
oxide) and SmCl3.6H20. The macroporous structure is
obtained by concurrently inducing the phase separation and sol-gel transition.
Using a visible laser with the wavelength of 590 nm, the valence state of Sm2+
has been manipulated spatially. When the photoionization of Sm2+ is
combined with multiple light scattering in the porous glasses, holes are burned
in wave-vector domain. The hole profile can be controlled by the macroporous
morphology.
Strong high-quality fibre Bragg gratings, with photoinduced
refractive-index modulations of more than 10-3, were written in fibres of
various types by third-harmonic radiation (267 nm, 300 fs and 6-9 x 1010
W/cm2) of a femtosecond Ti:sapphire laser. It was shown that the
267-nm photosensitivity responses of the fibres of the fibres may be higher
than in the case of deep UV 157-nm F2- laser irradiation. The
annealing characteristics of the fabricated gratings point to a photochemical
nature of the induced refractive index.
* Electrical and Computer Engineering Department, University
of Maryland, College Park MD 20742, USA
Optical properties of nano-hole arrays in thin metallic
films, related to surface plasmon polariton excitations, have been studied.
Such nanostructured films reveal strong light-polarisation related effects of
the enhanced optical transmission.
Initial and radiation-induced loss spectra are analyzed
in three multimode holey fibres with a high-OH KU-1 silica core. A fibre with
an optimized cross-section is shown to have no leakage loss. A high
concentration of gamma-radiation-induced non-bridging oxygen is argued to be
due to a high cooling rate during fibre drawing.
Large core silica holey fibres with a limited number of
air channels in the cladding are investigated theoretically and experimentally.
An impact of the relative hole diameter on single-mode operation, the fiber
transmission, an bending loss is addressed.
Molecular sieves are crystalline solid state materials
with crystallographically defined nanometer size pores. This property
stimulates attempts to use the sieves as an ordering framework for arranging
optically functional molecules, so creating a compound material with new
optical properties. It has been possible to induce laser emission in AlPO4-5
crystals filled with organic dye material. Lasing in this compound material
occurs in micrometer size ring resonators, in which the laser mode is confined
by total internal reflection at the natural hexagonal crystal side faces
resembling a whispering gallery mode. As the compounds are synthesized with the
inexpensive method of hydrothermal growth, already in laboratory scale we can
obtain several grams of microlasers, or "lasing powder".