inside the optical networks… a closer look to the amplifiers part ii hop ton that
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Inside the optical networks…A closer look to the amplifiers
Part II
Hop Ton That
Traditional Configuration of WDM Systems
Optical amplifier type
2 major classes: Semiconductor Optical Amplifiers (SOA)
conventional SOAGC-SOA (Gain-Clamped SOA)LOA (Linear Optical Amplifier)
Fiber Optical amplifiers (FOA)Rare earth-Doped Fiber Amplifiers
Erbium-Doped Fiber Amplifiers (EDFA) : C, L-Band
Thulium-Doped Fiber Amplifiers (TDFA) : S-BandPraseodymium-Doped Fiber Amplifiers (PDFA) : O-Band
Other optical amplifier type
Not based on stimulated emission but on nonlinear effects
Fiber Raman AmplifiersDiscrete Raman AmplifiersDistributed Raman Amplifiers (DRA)
Hybrid EDFA/Raman Amplifier
EDFA: Pumping mechanism
EDFA Configuration
Co-propagating pump= lower noise butlower output power
Counter-propagating pump= higher outputpower but higher noise
EDFA Noise
Output vs wavelength
Amplification between 1.53 and 1.56 um.
Rare earth (Er, Tm, Pr) -Doped Fiber Amplifiers
Gain band:Er (C, L-Band), Tm (S-Band), Pr (O-Band)
76 nm (1532-1608 nm) record gain bandwidth in single band configuration [M. Yamada et al.,OFC’98PD].- Flat gain: 21 dB, Noise figure: 7 dB- Gain equalizer: two MZ filters with FSR of 32 and 120 nm
1.48 mpump LD
WDM coupler
1.48 mpump LD
WDM coupler
Tellurite EDF 1 2
4 m 10 m
IN OUT
MZ Gain EQ.
M. Yamada et al., OFC’98 PD, PD7, 1998
Stimulated Scattering
is transferring energy from the incident wave to another, scattered wave at lower frequency (longer wavelength) with the small energy difference being release as phonons.
The incident wave can be seen as a pump wave.
(Scattered waves are called Stokes waves)
Stimulated Scattering
2 types:- Stimulated Raman Scattering (SRS) - Stimulated Brillouin Scattering (SBS)
In WDM systems, SBS has almost no effect
Distributed Raman Amplifier (DRA)
DRA is based on Raman Scattering.
A large pump is co-launched at a lower wavelength than the signal to be amplified
Typical Raman Gain Curve versus Wavelength
DFA vs DRA
Hybrid EDF/Raman Amplifier
Gain bandwidth of optical amplifiers1660 nm1640162016001580156015401520150014601440 1480
1660 nm1640162016001580156015401520150014601440 1480
Fluoride EDFA 62 nm
EDFA 52 nm
EDFA ~47 nm
Tellurite EDFA 76 nm]
TDFA 37 nm
TDFA 35 nmRaman + Fluoride EDFA 80 nm
Dist. Raman + Fluoride EDFA 83 nm
Raman + TDFA 53 nm
Raman 18 nm
Raman 40 nm
Raman 100 nm
Raman 132 nm
C-Band L-BandS-Band U-BandE-Band
Fiber Raman Amplifiers
Gain band: 1.3~1.7 um (tunable by pump wavelength)
132 nm record gain bandwidth in double band configuration has been achieved [H. Masuda et al., ECOC’99].- Combination of Distributed Raman amplifiers (DRA) and discrete Raman- Two-gain-band Raman amplifier
1.475 mpump LD
W DM coupler
1 .465 m1.495 m1.510 mpum p LD
W DM coupler
R a m a n fiber II8.3 km
I I I5 .0 k m
IN
OUT
MZ Ga in EQ .
H. Masuda et al., ECOC’99, II-146, 1999
1.545 mpum p LD
IV5.0 km
1.545 mpum p LD
R a m a n fiber I5.0 km
1.545 mpum p LD
Com binerDivider
1 .415 mpum p LD
W DM coupler
DSF 50 km
Distributed gain
Discrete gain
Companies working in the optical transport network technology field.
Europe Nokia, Ericsson Telecom, Ericsson Comp., Telia, Sonera, Teledanmark, Lucent Nederlands, BT, Marconi, Nortel Networks(Euro), Siemens, Swisscom, France Telecom, ……Italtel, Telecom Italia, Alcatel SEL, Alcatel Italy, Pirelli, Telecom Italia, CSELT, Ukraine, Marconi
North America AT&T, Corning, Ciena, EXFO, Elisa, Fujitsu Networks(US), JDS, Lucent(US), Hitachi Telecom(US), Motorola, NEC(US), Nortel, Networks(US, Canada), MCI Worldcom, Sprint, Telcordia, Tycom, Ciena, Cisco
Asia China Telecom, China Unicom, CLPAJ, Corning Int. DDI, ETRI, Fujitsu, Hitachi, Huawei Technol., Japan Telecom, Korea Telecom, KDDI, Mitsubishi, NEC, NTT, Oki, Shanghai Bell, Sumitomo, Sumsung, Toshiba
Bibliography
www.google.com Télécommunications par fibres
optiques: Historical part www.unice.fr/dess_ntic: flash
animations Raman Amplification Design in
WDM Systems (IEC Tutorial) www.iec.org/online/tutorials/raman
Book: Fiber-Optic Communications Technology, course book.
Questions
The end!
Thank you for your patience!