JRA6: Picosecond pulse sources for ultrahigh bitrate communication

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JRA6 Picosecond pulse sources for ultra-high
bit-rate communication

• Coordinator Herbert Venghaus (venghaus_at_hhi.de)
• Deputy Coordinator Mark Thompson
  (mgt32_at_cam.ac.uk)

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JRA 6 Objectives

• Develop picosecond pulse sources for the
  telecommunications market
• Monolithically integrated and compact
• High repetition rate (10GHz 50GHz )
• Short pulse generation (1 - 3ps)
• Low noise performance

• Typical application
• 40Gb/s and 160Gb/s long haul data transmission

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Targets 2004
Research
Integration

• Advanced device modelling
• Key parameters (pulse duration, stability,
  jitter, etc.)
• Novel device concepts
• Fabrication
• 40GHz mode-locked lasers
• Characterisation
• Noise performance
• Pulse duration, profile and chirp
• System implementation
• High speed data transmission

• Multi partner CAD suites
• Comparative modelling and experimental studies
• Partner exchanges
• Publications

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Integration concept
Role and interaction of Partners
FAA1
FABRICATION
MARKET WATCH
MODELLING
CHARACTERISATION
UC3M
CAM
HHI
COM
BOOKHAM
POLITO
All Final assessment in view of different
application areas
Partner interaction (exchange of devices,
results, know-how, scientists !)
ePIXnet related senior exchange
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Results on integration targets

• Exchanges
• 3 junior research exchanges
• 2 senior research exchanges
• Publications
• 22 Conference publications (7 invited)
• 11 Journal publications
• 2 Joint publications
• Important integration activities
• Advanced device modelling collaboration
  established POLITO, CAM, HHI, UC3M
• Multi partner applications study
• Established fabrication link with FAA1

ePIXnet related senior exchange
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Results on research targets

• Modelling
• Comparative modelling study and consolidation of
  modelling parameters (POLITO, CAM, HHI, POLITO,
  UC3M)
• Novel device concepts and mode-locking dynamics
  (CAM, POLITO)
• Detailed absorber modelling (POLITO, HHI))
• Fabrication
• Successful fabrication of 40GHz sources (HHI)
• Submission of advanced pulsed laser designs to
  FAA1 (CAM, TUE)
• Characterisation
• Assessment of pulse quality (jitter, pulse
  duration, chirp, pulse shape, etc)
• Detailed investigation of both QW and QD lasers
  (CAM, COM, HHI)
• Record low noise performance (COM, HHI, CAM)
• Sub picosecond pulse generation in QD pulsed
  laser (CAM)
• Record high repetition rate QD lasers
• System implementation
• 160Gb/s transmission over 480km (HHI)

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Highlights Advanced device concepts

• FM mode-locking (CAM)

CLEO 2005
OCDMA code generation (CAM)

• Fully integrated OCDMA sources using
  multi-grating cavity MLLDs
• Orthogonal codes generated is investigated
• Each code representing a single user

CLEO PR 2005
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Highlights Fabrication

• Monolithic 40/42/43/53 GHz mode-locked laser
  chips (HHI)

InP-based buried heterostructure lasers
fabricated at HHI
Saturable absorber
Rear facet HR coated
Gain
Additional phase tuning elements
DBR
Target parameters ? 1552 nm --gt 1556 nm f
40GHz to 53GHz ?? 1.5 2.5ps
Output facet AR coated
Initial mode-locking results
Tight tolerances achieved
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Highlights QW noise performance
Ultra low noise performance QW lasers (HHI, COM)
Residual phase noise (COM)
Amplitude noise (HHI)
160Gb/s target
Published in J. Opt. Soc .Am. B., 2006
CLEO / PTL 2005

• 40GHz mode-locked lasers are characterised for
  noise performance.
• Low noise design strategies identified
• Record low noise performance
• lt1 amplitude noise
• 110fs (20kHz - 80MHz) timing jitter at 10GHz
• 73fs (20kHz - 320MHz)timing jitter at 40GHz

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Highlights QD noise performance

• 40GHz QD hybrid mode-locking study (JRE, CAM?
  COM)

Phase noise
Timing jitter

• First demonstration of 40GHz hybrid mode-locking
  in a QD laser
• Hybrid jitter performance of 124fs (20kHz
  320MHz)
• Record low passive mode-locking jitter
  performance of 219fs (16MHz 320MHz)

Accepted for ECOC 2006
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Highlights Sub picosecond pulses

• High power, short pulse QD mode-locking (CAM)

500mW peak power 10mW average power
4µm
100µm
Tapered Device
800fs pulse width
10mW peak power 0.5mW average power
6µm
Uniform Device
2ps pulse width
ECOC / APL 2005

• Tapered waveguide design implemented for
• Increased output power
• Enhanced saturation ? reduced pulse width
• Single mode operation

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Highlights High repetition rate

• 240GHz QD harmonic mode-locking study (CAM)

• 1st, 2nd, 3rd and 6th harmonic demonstrated on a
  single device
• 240GHz record high repetition rate for a QD
  mode-locked lasers

Accepted for LEOS 2006
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Highlights Applications

• Laterally mode-locked lasers (UC3M)

• Allows for narrow band transmission of signals
  above the intrinsic relaxation oscillation
  frequency
• Potential low-cost transmitters for radio over
  fibre

Ultra high speed data transmission (HHI)
160Gb/s, 480 km transmission with error-free
performance
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Additional Work

• Telecommunications market realignment
• 160Gb/s line rates no longer main focus
• Extensive applications study performed
• Photonic samples, optical interconnects, clock
  distribution, RF over fibre
• Change in available resource at HHI
• Reduced fabrication effort for HHI
• Fabrication initiated effort with FAA1
• Assessment of new material systems
• Detailed investigation of QD laser for
  mode-locking

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Most valuable outcome of this activity

• Realisation of state of the art QW mode-locked
  laser sources
• Ultra low jitter performance
• Reduced amplitude noise
• Data transmission demonstration at 160Gb/s and
  over 480km
• Realisation of state of the art QD mode-locked
  laser sources
• Sub-picosecond pulse generation
• First demonstration of 40GHz hybrid mode-locking
• Ultra low passive jitter performance
• Identification of design strategies for QW and QD
  sources
• Demonstrated the potential of QD laser for
  mode-locking

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Short pulse dynamics and applications of
integrated semiconductor devices
Continuation
JRA Short Pulses

• Coordinator Mark Thompson (mgt32_at_cam.ac.uk)

• Connection to platforms
• - InP fabrication
• - Packaging
• - High speed characterisation
• - JRA InP QD

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Short Pulse JRA Objectives

• Develop the next generation of semiconductor
  pulse sources to rival solid state and fibre
  lasers in niche applications.
• Target applications
• Medical scanning, imaging and surgery
• Optical instrumentation and optical sampling
• Optical radar
• Metrology and sensors
• Clock distribution
• Communications
• Step advance in device performance is required to
  reach these targets
• All semiconductor short pulse technologies need
  to be pushed to reach these goals

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Short Pulse JRA Research Activity
VECSEL
High rep rate
SESAM
Monolithic
Edge emitters
Vertical emitters
High power
Low jitter
Short Pulse JRA
InP fabrication
JRA InP QD
Photonic packaging
High speed characterisation

• Combine the strengths of JRA5 and JRA6
• The common goals of this activity will be
• Identification and exploitation of new and
  emerging applications for short pulse
  semiconductor lasers sources
• Focus on improvement of key application related
  parameters
• Development of new device concepts
• Enhance understanding through modelling and
  dynamic experiments

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New Targets
Research
Integration

• Advanced device modelling
• New device concepts
• high power
• short pulse devices
• Integrated VECSEL sources
• Low repetition rate monolithic pulse sources
• QD short pulse devices
• Novel bulk and QW devices

• Road mapping activity
• Comparative device study between partners
• Device exchanges
• Partner exchanges
• Publications

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Partners and structure

• 8 academic partners
• 2 industrial partners
• 3 platforms
• 1 interaction with external JRA

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Main aims and objectives

• Detailed road mapping study
• Comparative study of state of the art
  mode-locking devices (VECSEL, edge emitters, QW
  and QD)
• Development of low repetition rate (1GHz
  2.5GHz) monolithic mode-locked lasers source
• Realisation of compact VECSEL structure with
  integrated emitter and absorber
• 3 junior exchanges and 1 senior exchange
• 4 joint publications

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Extra slides
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Short Pulse JRA Research Activity
Power limits
Communications
Integration
Characterisation
Fabrication
Signal processing
VECSEL
Pulse duration
Targets
Activities
Applications
QD
Bio-medical
Design understanding
Road mapping
Noise performance
Clock distribution
Short Pulse JRA
CAM COM POLITO UC3M ETHZ TUE-HGF
TUE-OED LPN-CNRS BOOKHAM FILTRONIC (new
ePIXnet partner) InP platform HSC platform
Packaging platform JRA - InP QDs

• Highly integrated activities
• Broad range of partners expertise to cover all
  core topics
• Innovative devices

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Highlights Advanced modelling

• Advanced absorber modelling (JRE, POLITO? HHI)

• Experimental studies performed at HHI are used
  to develop an absorber model for use in the
  POTLIO mode-locked laser model

• Simulation results are comparable to HHI
  experimental results

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Partners Who does what?

• CAM Modelling and design of advanced
  mode-locking structures. Particular interest in
  low repetition rate monolithic source and quantum
  dot sources.
• COM Interest in QW edge emitter and VECSEL
  structures. Experience in advanced measurement
  techniques (residual jitter, etc). Processing of
  QW and QD edge emitters
• POLITO Modelling support with emphasis on short
  pulse and high power mode-locking in QW and QD
  edge emitters
• UC3M Dynamic short pulse characterisation and
  modelling. Experience in short pulse bio medical
  applications
• ETHZ Extensive experience is VECSEL mode-locking
  structures. Fabrication and characterisation
  facilities for both VECSEL and SESAM device.
• TUE-HGF Strong interest in the application of QD
  material to short pulse dynamics. Supply of QD
  material to the JRA
• TUE-OED Modelling, design and characterisation
  of ring laser structures. Interest in the
  application of QD material to mode-locking
• LPN-CNRS Strong interest in the development and
  fabrication of half-VCSEL structures for
  electrically and optically pump pulse sources
• BOOKHAM Industrial guidance on exploitation of
  short pulse technologies
• FILTRONIC (new ePIXnet partner) Expertise in
  high frequency electronics and photonics, with
  particular interest in compact broadband sources
  for photonic signal processing
• InP platform Fabrication of novel mode-locked
  laser sources
• HSC platform Advanced device and system
  characterisation of state-of-the art devices
  developed with the JRA
• Packaging platform Packaging of devices to
  facilitate system integration
• JRA InP QDs Strong interest in the use of QD
  devices in short pulse applications (pulse
  generation and amplification)

JRA3 JRA-QD arrays