Bez nadpisu

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Modélisation de lamplificateur à fibre silice
dopée thulium
Pavel Peterka un post-doc du groupe Fibres
optiques dopées LPMC, fibres dopées
thulium Bernard Dussardier, Wilfried Blanc,
Basile Faure, Fabrice Ubaldi, Adel Ibrahim,
Gérard Monnom Séminaire LPMC, 23 mai 2003
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D'où je viens ?
Prague
Nice
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Outline

• TDFA Introduction
• Typical results of the model
• Description of the model
• Input parameters
• Optimization issues
• Conclusions
• IREE Prague

Séminaire LPMC, 23 mai 2003
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Available bandwidth for WDM


Séminaire LPMC, 23 mai 2003
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Thulium reported emissions
Séminaire LPMC, 23 mai 2003
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Upconversion pumping schemes
Komukai95 T. Komukai et al., IEEE J. Quantum
Electron., 31(11)1880-1888, 1995 Aozasa01 S.
Aozasa et al., El. Lett. 37(19) 1157-8, 2001
Séminaire LPMC, 23 mai 2003
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Upconversion pumping schemes
Komukai95 T. Komukai et al., IEEE J. Quantum
Electron., 31(11)1880-1888, 1995 Aozasa01 S.
Aozasa et al., El. Lett. 37(19) 1157-8, 2001
Roy01 F. Roy et al., OFC'01 PD2-1-3 vol.4,
2001 Cole01 B. Cole and M. L. Dennis, OFC'01,
Anaheim, USA, 2001, TuQ3 Kasamatsu99 T.
Kasamatsu et al. Opt. Lett., 24(23)1684-1686,
1999 Kasamatsu01 T. Kasamatsu, et al., IEEE
Photonics Technol. Lett.,13(5)433-435, 2001
Roy01a F. Roy and A. Le Sauze and D. Vallart,
In Tech. Digest of OAA'01, Stresa, Italy, July
1-4, paper PD4, 2001 Gomes03 A. S. L. Gomes et
al., IEEE Photonics Technol. Lett.,
15(2)200-202, 2003
Séminaire LPMC, 23 mai 2003
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Suitable reliable host material

• Majority of the TDFA modules is based on fluoride
  Tm-doped fibres.
• It results in difficulties with
• Fusion splicing to standard telecommunication
  fibre
• Fabrication
• Robustness (hygroscopicity) and aging

• Motivation to develop the silica based TDFA
• Compatibility with standard telecommunication
  fibre.
• Environmental stability.
• Potentially easy fabrication.
• Gain of 12 dB Cole01, Ohara02 and 20 dB
  Samson00 in silicate fibres were
• reported experimentally.

Séminaire LPMC, 23 mai 2003
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TDF theoretical modelling overview

• 1991 800 nm amplifier, Carter et al.
• 1995 rate equation model of Komukai et al. ? the
  upconversion pumped S-band TDFA behave as a quasi
  three-level amplifier. No amplifier performance
  simulation.
• 1999 numerical model of 1900 nm MMF laser by
  Jackson and King
• 2001 numerical model of S-band TDFA, Lee et al.
  Used for optimization of specific case of single
  wavelength upconversion pumping.
• 2002-3 two other numerical models of S-band
  TDFA, fluoride glass fibre host, PhD thesis of
  Fabien Roy (Alcatel) and T. Kasamatsu (NEC Corp.,
  Japan)
• Aims of our numerical modelling
• Predicting the S-band amplifier performance
  under different
• pumping schemes.
• Physical insight.
• Optimisation of the pump wavelengths, powers,
  fibre length ...

Séminaire LPMC, 23 mai 2003
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Standard outputs of the TDF model
Séminaire LPMC, 23 mai 2003
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Standard outputs of the TDF model
Longitudinal Position, z m
Séminaire LPMC, 23 mai 2003
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Standard outputs of the TDF model
Longitudinal Position, z m
Séminaire LPMC, 23 mai 2003
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Standard outputs of the TDF model
Séminaire LPMC, 23 mai 2003
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Standard outputs of the TDF model
Séminaire LPMC, 23 mai 2003
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Energy level diagram of thulium
Aij ... spontaneous emission i ? j
Anrj ... nonradiative decay rate from the level
j Wij ... stimulated absorption/emission i ? j
Anr2, Anr4 are very large ? N2, N4 ? 0 ? 4
rate equations for N0, N1, N3, N5 while Ntot ?
Ni
Séminaire LPMC, 23 mai 2003
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Propagation of lightwaves in the fibre
Analogical differential equations hold for the
powers P -(?) propagating in negative
direction. The fourth-order Runge-Kutta-Gill
method is used to integrate the equations. Since
some boundary conditions are not known in the
beginning of integration an effective iterative
algorithm was used.
Séminaire LPMC, 23 mai 2003
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Input parameters Tm spectroscopy
cross section shapes Jackson99, Roy02,
fluorescence lifetimes Jackson99, Cole01,
Faure02 Other unknown spectroscopic
parameters are estimated using Judd-Ofelt
analysis (branching ratios, radiative lifetimes).

Séminaire LPMC, 23 mai 2003
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Input parameters core profile
Séminaire LPMC, 23 mai 2003
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Optimization of the TDF length
lpump1064 nm t341 ms
Séminaire LPMC, 23 mai 2003
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Optimization of the pump wavelength
Séminaire LPMC, 23 mai 2003
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Conclusions

• Comprehensive, spectrally and spatially
  resolved numerical model
• of S-band TDFA was developed.
• The model is general in terms of number of
  pumps, their
• wavelengths and the fibre type (e.g. silica
  ZBLAN).
• WDM gain prediction.
• Optimization of the fibre length and the pump
  wavelength.
• What next ?
• Refining the input parameters (absorption
  measurement for the
• Judd-Ofelt analysis and the fluorescence
  lifetime measurements).
• Optimization of fibre waveguide parameters
  (fibre core radius,
• LP11 cutoff), dopants (to avoid concentration
  quenching).
• Time resolved model.

Séminaire LPMC, 23 mai 2003
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Institute of Radio Engineering and
Electronics Academy of Sciences of the Czech
Republic
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Institute of Radio Engineering and
Electronics Academy of Sciences of the Czech
Republic

• Waveguide Photonics Group
• soliton (short-pulse, high repetition rate)
  fibre lasers
• fibre optic measurement (COST 265)
• special optical fibres (rare-earth doped fibre,
  twin-core fibres, )
• hybrid (EDFA and Raman) fibre amplifiers
• microstructure fibers
• oscillator at 1315 nm for 3 TW, 1.2 kJ pulsed
  laser system Asterix
• Other activities in Photonics
• evanescent field fibre sensors
• surface plasmon resonance sensors
• integrated optics and photonic crystals

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Modulation instability fibre laser
The autocorrelation function (up) and the
optical spectrum of the output pulse train
The laser setup
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Výzkum MOV v ÚRE AV CR
Grantový projekt GACR 102/02/0779 Mikrostrukturn
í vlákna typu kremen-vzduch metody jejich
prípravy a charakterizace. (reitel Vlastimil
Matejec) V soucasné dobe probíhají technologické
experimenty zamerené na prípravu preforem MOV a
jejich taení a na merení experimentálních MOV.
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Laboratory of Active and Nonlinear Fibre Optics
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Estimation of the multiphonon nonradiative decay
rate in glasses according to Desurvire's EDFA's
book, p. 223-224
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Test of the model functionality
The model of the thulium doped fibre was tested
by its comparison with the model of the fibre
laser in Fabry-Perot arrangement Jackson99.
Fibre parameters Tm concentration. 3000 ppm
fibre length 0.924 m core radius 10 mm sa(1064
nm) 1.26 x 10-26 m2 sa(1216 nm) 4.605 x 10-25
m2
Input/output laser characteristic. The laser
threshold and the slope efficiency determination.
WOWTNM Prague 2003, 4-5 May 2003
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Test of the model functionality
Solid lines are the tested results and dashed
lines are the results of Jackson99. Dotted line
represents a threshold calculated using an
analytical formula derived in Chen92. Relative
errors are evaluated for the wavelength of
maximum absorption, i.e. 1216 nm.
WOWTNM Prague 2003, 4-5 May 2003