COST 288 Action Nanoscale

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COST 288 ActionNanoscale Ultrafast Photonics

• Chairperson
• Dr. Judy Rorison,
• University of Bristol, U.K.

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Outline

• What is TIST-COST?
• Role for the COST 288 action
• -world scene for telecoms/data communications
• -USA, Japan, Europe
• Structure of COST 288
• 3 Working Groups
• Round-robins measurements, modelling comparisons
• Short Term Scientific Missions (STSMs)
• Meetings/Workshops
• Conclusions

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What is COST ?

• Intergovernmental RD Cooperation
• Created in 1971
• Governed by Council of Europe
• 12 Scientific and Technical Domains
• Participation
• 34 COST Countries
• International Organisations
• 200 Actions
• Multilateral MoU
• Concertation of nationally funded RD
• Funded from the EU 6th Framework Programme
• Managed by European Science Foundation
• 50-80 M 2003-2006

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COST Countries

• COST Member States
• ? The 25 EU Member States
• EFTA Member States ? Iceland ? Norway ?
  Switzerland ? Candidate Countries ? Bulgaria ?
  Croatia1 ? Romania ? Turkey? Other
  Countries ? Serbia and Montenegro1 ? FYR of
  Macedonia (FYROM)1
• COST Co-operating States ? Israel

1 Not Associated to FP
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COST Domains

• Agriculture, Food Sciences and Biotechnology
• Chemistry
• Environment
• Forests and Forestry Products
• Materials
• Medicine and Health
• Meteorology
• Physics
• Social Sciences and Humanities
• Telecommunication, Information Science and
  Technology
• Transport
• Urban Civil Engineering

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TIST Research Domains
e-Society
User Aspects
Human-Machine Interface
Wireless Systems
Bio-Info Genomics
Network Design Analysis
Biometrics Security
Distributed Computing Software Architectures
Nanotech Photonics
Information Management Multimedia
Antennas Propagation
Telecommunications
Information Systems
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Research Domains Actions
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TIST participation

• Academic participants
• stimulation of research activities
• Geographical balance
• Average Action 16 Countries
• Involvement of industry
• Direct Involvement / pre-competitive
• Through regulatory / standardisation bodies

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TIST Scientific activities

• Sharing / pooling of data
• Common analysis
• Confidential internal reports
• Workshops
• Exchange Missions
• PhD project support

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TIST results

• Standardisation
• ITU / CEPT / ETSI
• Scientific publications
• Contribution to the ERA
• 6 NoE in the FP6
• Link with IST / Eureka clusters
• EC DG INFSO / DG Research
• Industrial spin-off
• SMEs founded

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COST in theEuropean Research Area
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Dissemination of results

• Standardisation
• ITU
• ETSI
• Reference publications
• 3GPP
• WHO
• Industry

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Evolution of Optical Communications - trends up
to 2000
Line systems of well above a Tbit/s will be
required by the year 2010. Current Time Division
Multiplexing or TDM techniques will no longer be
sufficient to support these enormous traffic
demands - ACTS HORIZON
next generation
10000
Ethernet Standard
1000
100
WDM
Telecoms increase at 60 per year
10
SDH
Capacity in Gbit/s
1
PDH
0.1
0.01
Year
0.001
1990
1994
1998
2002
2006
2010
2014

• Ethernet standard - 10 times data rate increase
  every 2 years!
• Physical Layer will shortly become the rate
  Limiter

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Telecoms and Data Communications

• Quantum jumps are needed for improved
  communications-gt new physical layers
• Need cheap high performance for data/tele-comms
• Worldwide addressing
• -USA - spectral slicing ultra-fast programme
• -Japan FESTA ultra-fast programme
• -UK Ultra-Fast Physics consortium (UPC)
• -Europe active groups/ FW 6-gt good for COST
  focus!

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Spectral Slicing-Novel Ultra-Fast Technique
25 THz
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COST-Nanoscale and Ultrafast Photonics

• AIM to study ultrafast nanophonics
• APPLICATION in the high capacity photonic
  communication infrastructure
• (Tele Data communications)
• Building on previous telecom COST actions
• 267 -Photonic Devices and subsystems for high
  capacity optical networks
• 268-Wavelength scale photonic components for
  telecommunications
• 240-techniques for modelling and measuring
  advanced photonic telecom components

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Nanoscale and Ultrafast Photonics

• Forum to bring forward novel topics
• Novel materials
  (GaInNAs quantum wells,
  Qdots, GaN, GaAsSb/GaAs)
• Micron-scale featured refractive index profiles
  
  (gratings, photonic crystal structures, VCSELs)
• Advanced Optical Signal Processing and Optical
  Logic
• quantum communications
• Evolutionary Revolutionary

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Nanoscale and Ultrafast Photonics

• Methodology
• Exchange of information through MCM WG meetings
• Set-up collabor. round-robin measure. modelling
  exercises, STSMs
• Distribution platform for materials, devices
• Link with potential manufacturers and system
  users
• Meetings (MCM/WG)
• -Brussels(07/04/03)-kick-off /introduce groups
• -Turin (18/09/03)-propose round-robin exp and
  model
• -Athens(01/06/04)-check progress, new round
  robins (EPIC)
• -Rome(18-20 /10/04)-check progress, link with
  COST P11
• -Metz(31-1/(04-05)/05)-workshop on
  WG2,round-robin update
• 4 STSM completed in first year/ 7 STSM in second
  year
• Joint meetings with OPTIMIST, EPIC and COST P11

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Nanoscale and Ultrafast Photonics
ChairJ. Rorison, CV G. Morthier
Working Group structure
WG1Novel Gain Materials and Fabrication
Techniques Chair N. Balkan, VC Andrea Fiore
-GaInNAs QWells, QDots, PBGs
ultimate performance, quantum information
processing
WG2 Photonic Devices Chair J. Danckaert, VC
M. Sciamanna
- Phosphide and
GaAs-based edge-emitters and VCSELs, optical
feedback, new regimes of operation, higher
functionality,non-linearities

WG3 Ultrafast and Non-linear Photonic Devices
Chair E. Bente, VC D. Lenstra, I. Zacharopoulos

-testing novel devices in
systems test-beds/ novel set-ups
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Nanoscale and Ultrafast Photonics
Working Group structure
WG1 Materials devices
Devices
Devices
System requirements
Parameter extraction, design
Devices and novel concpts
WG2 Device physics
WG3 Dynamics and systems
System requirements
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• WG1 Activities-New Active materials give rise to
  new device physics and new functionalities
• GaInNAs QWells and self-organised InAs QDot
  lasers
• GaInNAs-higher gain than GaInAsP
• -faster modulation speed
• -grown on GaAs-easy to fabricate VCSELs
• -broadband gain-broadband SOA?
• QDot- low but broad-band gain (broadband SOA)
• -fast modulation speed (with tunnelling
  injection/p-dooping)
• -grown on GaAs-VCSELs
• -low a factor (low chirp, low feedback
  sensitivity)
• -different physics-coupling with wetting
  layer
• (signal processing applications)
• -possibility for single photon generation
• quantum information processing (QIP)
• Samples QDEPFL (for a-factor RR) and ring
  lasers (Glasgow-being fabricated), GaInNAs QW
  Tampere CNRS((for a-factor RR)/ VCSELs

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WG1-GaInNAs Quantum wells
Modelled small signal modulation Response of
GaInNAs Qwells
Modelled Peak gain of GaInNAs compared with
GaInAsP and AlGaInAs
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WG1-The THH WC STSM (Essex-Toulouse)
?1 cw (pump laser
signal carrier) ?1 (Pulsed)
?2 (pulsed and amplified)
SESAM
TOP HAT HELLISH VCSOA
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WG1 Self-assembled QDs Applications
QD SOA (Fujitsu, OFC 2004)
1300 nm QD laser (EPFL)
QD single-photon source
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WG1-Single photons at telecom wavelengths
Application Quantum cryptography
Single QD
Bob
Alice
0101...
f
Single-
Emits one photon at a time
emitter
0101...
Eve
Low-density QDs in a m-cavity
filter
Characterisation STM mission EPFL-NNL Lecce
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WG2 Activities

• Measures the device performance of the devices
  made of the novel materials from WG1.
• Investigates novel physics in devices subject to
  feedback looking for novel functionality
• Investigates novel control of devices through the
  incorporation of grating structures or PBGs into
  devices.

• WG2 Activities
• Roundrobin Test Measurements on ?-factor
• Spatio-temporal and polarization modelling of
  VCSELs.
• Study (exp, num theor) high frequency dynamics
  of VCSELs, also when subject to optical feedback,
  opt. injection, self-pulsing in VCSELs,
• Samples EE from WG1, VCSELs (self-organised-
  GaAs-based not new materials)
• STSMs polarisation dynamics in VCSELs, strain
  /dichroism in VCSELs

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WG2 Line width enhancement factor of new types
of semiconductor lasers

• The line width enhancement factor (?factor)
  great importance for the dynamics of
  semiconductor lasers (low ?factor is typically
  good)
• The ?factor directly influences laser line
  width, chirp under current modulation (important
  for long distance and high bit-rate
  transmission!), mode stability, filamentation in
  broad-area high-power lasers, optical injection,
  optical feedback, mode coupling
• Open issues standard measuring method ???
• Roundrobin test measurements on ?-Factor
• (coord. G. Giuliani, U. Pavia, Italy)
• GOAL compare different measurement methods
  applied to different types of devices
• Devices under test both consolidated and novel
  lasers
• DFB-lasers, VCSELs, QuantumDots / QDash lasers,
  New material lasers (GaInNAs/GaAs,
  InGaAs/InAlGaAs), Q-Cascade lasers (STSM from
  Darmstadt to Pavia),

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WG2 Line width enhancement factor

• Commercial devices
• F-P 850 nm 50 mW available
• DFB 1550 nm 50-150 mW available soon
• DFB 1550 nm 6-20 mW available
• DFB 1300-1550 nm AlInGaAs Modulight
  (SF) available soon
• VCSEL 780/850 nm 1-2 mW available
• Research-grade devices
• QDs
• EPFL (CH) laser bar available
• TU Berlin (D) mounted ?
• UIUC (USA) ?
• CNRS-LPN (F) ?
• Diluted nitride
• ORC VCSEL - Modulight (SF)
  available soon
• CNRS-LPN (F) ?
• AlInGaAs
• ORC EEL - Modulight (SF)
  available soon
• Glasgow Uni (UK) laser bar available
• QC-TU Darmstad available

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Devices vs. Measuring Methods
FM/AM
Chirp
Opt inject feedb
linewidth
H-P
FP-850
DFB-1550
VCSEL
QDots
GaInNAs
AlInGaAs
QC
MM Multi-Longitudinal Mode devices (? method
not applicable ?)
Devices vs. Measuring Methods
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Groups / People

• provisional list
• (Belgium) - Vrije Universiteit Brussel - J.
  Danckaert / K. Panajotov
• (Finland) - ORC Tampere - M. Saarinen
• (Finland) - University of Helsinki - A. Lindberg
• (France) - CNRS/LPN - A. Ramdane
• (France) - Supelec Metz - M. Sciamanna
• (Germany) - Technical University Darmstadt - W.
  Elsäßer
• (Ireland) - Dublin City University- P. Landais
• (Ireland) - University College Cork - G. Huyet
• (Ireland) - Trinity College Dublin - R. Phelan
• (Italy) - University of Firenze - F. Marin
• (Italy) - University of Pavia - G. Giuliani
• (Sweden) - KTH - M. Chacinski
• (Switzerland) - EPFL Lausanne - A. Fiore
• (UK) - Bristol University - J. Rorison
• (UK) - Glasgow University - M. Sorel

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WG2 Polarization mode control in VCSEL with a
surface grating

• polarization instabilities in VCSEls
• solution surface grating
• Huge values of DICHROISM predicted by fully 3D
  and vectorial ELM model (but strong dependence of
  the dichroism on the grating depth )

No surface grating no fixed polarization
Perspectives study (theo, num, exp)
spatio-temporal and polarization dynamics of
VCSELs-Round-robin starting
K
H
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WG2 Study (numerical theoretical) of dynamics
of VCSELs ( optical feedback)

• Motivation
• Laser diodes are inevitably subject to optical
  feedback which may strongly impact their
  performances in optical telecommunications
• The dynamics of laser diodes when the optical
  feedback occurs very close to the laser output
  mirror short external cavity (EC) regime is not
  well known.
• An example of short EC regime the regular pulse
  package dynamics, recently unveiled
  experimentally (emission of fast pulses at the EC
  round-trip time, modulated by a slow envelop)
• Regime of small a-factor

• Perspectives
• Short Term Mission (STM) from Brussels to
  Darmstadt) on RPP dynamics in VCSELs, study of
  polarization dynamics.
• Study of the short EC regime and of feedback
  instabilities in small a new lasers structures
  (quantum dot devices, etc.)

T. Heil, I. Fisher, W. Elsäßer and A.
Gavrielides, Phys. Rev. Lett., vol. 87, 243901
(2001)
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WG3 Activities

• Highly performing ultrafast devices in relation
  to a telecommunication systems environment.(-from
  WG1 and WG2 and existing device modification)
• Current focus on ultrafast integrated sources,
  all optical switching and memory.

STSM AIT Athens (GR) and COBRA TU/e (NL)
All optical integrated
switching device. New Exp Round Robin on
Mode-locked Qdot (Berlin) laser
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WG3 Exercise Comparison of measurement methods
on waveguide MLL-LD
Goal Agree on measurement methods of output
specifications ultrafast diode laser sources.
Pulse duration, noise properties (amplitude,
timing jitter, ASE background, extinction
ratio). All relevant for system
application. Means Round robin exercise with a
modelocked semiconductor laser device. Status Ide
ntification of a device that is suitable for
traveling, suitable packaging. Possible devices
from COM, (Denmark) and HHI Berlin
(Germany) Involvement from COM (DK), COBRA(NL),
IMEC(B), MONOPLA partners
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WG 3 Exercise Parameter set definition for
simulation of waveguide MLL-LD
Goal Obtain a set of parameter value ranges for
SOA and saturable absorbers for use in design
simulation of ultrafast lasers. Optimization of
the epitaxial design of mode-locked
lasers Means Starting point established model
with parameter definitions. Definition of model
ultrafast laser. Testing the different models for
modelocking. Status Starting model selected
(from WAIS Berlin, D) MLL device from COM as
model laser Participation COM (DK), INTEC Gent
(B), WAIS Berlin (D), COBRA (NL), Pavia Uni.
(I), link to (MONOPLA program)
MLL studies by K. Yvind and J. Mork (COM) 1, 2
or 3 quantum wells
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WG3 Sub-picosecond pulse generation employing an
SOA-based nonlinear polarization switch in a ring
cavity COBRA Research Institute, Eindhoven
University of Technology, P.O. Box 513, 5600 MB
Eindhoven, the Netherlands X. Yang et al. OPTICS
EXPRESS 12 (2004) 2448
Measured autocorrelation function, demonstrating
800 fs pulses. Simulations indicate that 300 fs
pulses can be generated using this set up.
Sketch of set up for generating ultra-short
pulses. The novelty lies in the absence of a
saturable absorber, whose functionality has been
taken over by saturation induced polarization
anisotropy in the SOA.
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CONCLUSIONS Nanoscale and
Ultrafast Photonics-COST 288

• Status
• 3 strongly active WGs with strong links between
  them
• Generating novel research results (papers 31 in
  04/ 30 in 05)
• gt50 active groups involved
• Many STSMs linking groups
• Problems
• Action is large and broad advantages
  disadvantages
• Difficult to get WG1 new materials/devices (world
  problem)
• It has taken time to get round-robins going
• Action
• Need to work on fostering interactions beween WGs
• -hold meetings sequentially (rather than in
  parallel)
• Promote STSMs/enlarge broaden WG committees
• Have joint meeting with systems COST actions