next generation optical amplifier for 10 ’ s of tera-bps data transmission

Next Generation Optical Amplifier for Next Generation Optical Amplifier for 10’s of Tera-bps Data Transmission10’s of Tera-bps Data Transmission

Optical Communication Systems Lab.

Seoul National University

http://stargate.snu.ac.kr

KJISTFiber Optics Research Lab

SNUOptical Communication Systems Lab

National Research Laboratory Ultra-Wideband Optical Amplifier

2


Outline

Background History of Transmission Capacity Expansion Why WDM ? Why Ultra-Wideband Optical Amplifiers ? Market Aspects / Relation to Other Technologies Building blocks for Optical Amplifier

Technologies / Team potential Approach 1 : WEDFA Approach 2 : TDFA Approach 3 : Raman amplifier Approach 4 : Specialty fiber

Team profile / Approach / Goal



3


History of Transmission Capacity Expansion

AT&T10 Year Plans Did Not Give Sufficient Capacity

!! Always Beyond Expectation !!!! Always Beyond Expectation !!

Gb

/s

0.1

1

10 1

10 2

10 3

1980 1990 2000 20101970

1900 1950 2000 Yr1850

BL

(bp

s*k

m)

1

10 12

10 9

10 6

10 3

10 15

Telegraph

Telephone

Coax

MW

Lightwave

EDFA



4


Why WDM ?

FiberFiberFiberFiber

MUXLasers Detectors

AmplifierAmplifier

# of

WD

M c

han

nel

s

Bit rate per channel (Gbps)

10.1 1 10 100 1000

10 4

10 3

10 2

10Yr 96 - 97

WDM

1 Tbps

Yr 98 - 99

Yr 99 : 40G x 40chRaman Amp



5


Why Ultra-Wideband Optical Amplifier ?

Until the beginning of 1998, less than 10 published papers on Wideband EDFA

NTT 35nm 1450 - 1485nm Thulium 1998 NTT 37nm 1300nm region Praseodymium PCE < 20% 1998 NTT 75nm 1531 - 1606nm EDFA & Raman 1998 NTT 50nm 1460 - 1510nm TDFA & Raman 1999 NTT 110nm C & L plus Thulium PCE < 15% 1999 SNU 80nm 1530 - 1610nm C & L PCE > 27% 1999 Tyco 100nm formerly AT&T Raman Multi-pump 1999

Year 1999, Lucent Technology started to hire optical engineers for Raman Amplifier Development Year 2000, Raman amplifier became a preliminary product : Major effort by Majors

Silica-Er C+L band

Other Rare Earth

Raman Amplifier Raman Pump

RE Pump



6


Market Aspects / Relation to Other Technologies

실리카 계열 EDFA (WEDFA)

광섬유 Raman 증폭기

다른 희토류 이온을 첨가한 증폭기

A. 세계 시장 규모 ($)<초광대역 광 증폭기 >2000 년 :12 억 2005 년 : 32 억 +<광전송 장비 >2000 년 :40 억 2005 년 :120 억

B. 추가 광선로 포설 비용(km 당 3 억원 ) 절감

광전송 장비 / 기술 수출

기간망 구축 비용 절감

통신 수요의 안정적 공급

차세대

반도체 레이저수동광소자 특수광섬유

핵심기술

소자 기술

초광대역 광증폭기

대용량 전송 시스템



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Building Blocks for Optical Amplifier

1400 1450 1500 1550 1600 1650-2.0

-1.5

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

Gain

co

effi

cie

nt(

m-1)

Wavelength(nm)

Pump LD

Pump LD Pump LD

C band

L band

C + L C + L

Sub - optical components

Laser diode / photo diodeSpecialty FiberOptical IsolatorOptical coupler

AWG / FBGSpectral filters

Also a fundamental module for optical transmission system

Market price ~ 30K$since 1991

while..Component price dropped to

1/20 since 1991



8


WEDFA

1500 1520 1540 1560 1580 1600 1620 1640-50

-40

-30

-20

-10

0

10

20

L bandC bandOp

tic

al

Po

we

r (

dB

m)

W avelength (nm)

IEEE Photonics Technology Letters, vol. 12, May to be printed, 2000, 5 Wideband EDFA Patent (international) OSA Applied Optics, vol. 39, no. 7, pp. 1118-1120 2000, 4 EDFA sensor IEEE Photonics Technology Letters, vol. 12, pp. 329-331, 2000, 3 Wideband EDFA IEE Electronics Letters, vol. 35, pp. 1099-1100 1999, 6 Wideband EDFA OSA Applied Optics, vol. 38, pp. 2749-2751 1999, 5 EDFA sensor IEEE Photonics Technology Letters, vol. 11, pp. 316-318, 1999, 3 EDFA dynamics OSA Optics Letters, vol. 24, pp. 279-281, 1999, 3 Wideband EDFA Patent (international) IEEE Photonics Technology Letters, vol. 11, pp. 42-44, 1999, 1 Wideband EDFA Patent (international) IEEE Photonics Technology Letters, vol. 10, pp. 1721-1723, 1998, 12 WDM EDFA Patent (international) IEEE Photonics Technology Letters, vol. 10, pp. 1168-1170, 1998, 8 WDM EDFA Patent (international) IEEE Photonics Technology Letters, vol. 10, pp. 790-792, 1998, 6 WDM EDFA



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TDFA

1450-1520nm band can be utilized using TDFA and GS-TDFA Low loss region in optical fiber Not seriously explored until recent years We developed numerical model for TDFA for the first time (6 months of research)

Pump laser require specialty fiber (double clad, Yb doped fibers) Amplifier, pump laser, and fiber design require extensive numerical analysis

3H6

3F4

3H5

3H4

3F3

3F2

1G4

Pump Signal & ASE0

1

3

2

4

5Level

P1

P2

P3

1.47m Signal band

0.8m band ASE

1.8m band ASE

1450 1460 1470 1480 1490-40

-30

-20

-10

0

10

Gain &

NF

(dB)

Ou

tpu

t P

ow

er

(dB

m)

Wavelength (nm)

0

5

10

15

20

25

30

NF

Gain



10


Raman

Outperformthe most recent resultsfrom Tyco Submarine

(Simulation, May 1999)

plus

Derivation of new equation set for the much faster numerical analysis(IEEE PTL 2000)

1400 1450 1500 1550 1600

5

6

7

8

NF

(d

B)

Wavelength (nm)

1400 1450 1500 1550 16000

2

4

6

8

10

98nm 1dB bandwidth

Ga

in (

dB

)

0 5 10 15 20 250

50

100

150

Pu

mp

po

wer (

mW

)

Distance (km)

Amplifier dynamics based on nonlinearity in optical fiber (specialty fiber required) Each pump provides approximately 25 - 30nm of gain bandwidth Gain bandwidth, wavelength selectable with appropriate pumps



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Specialty Fiber : TDFA

ESA at 980 nm

PIQ at 1.55 m

980 nm

1550 nm1800 nm

1450 nm

Er3+Tm3+

OSA, Advanced Solid State Lasers, paper MB15 1999 , 1 EDF laser Optics Letters in preparation ASE source



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Specialty Fiber : pump

ErSm

1530nm 980nm

Pow

er D

ensi

ty

core

cladding

0

100

200

300

400

500

Sm

Ab

sorp

tion

(d

B/K

m)

1000 1200 1400 1600 18000.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

*1000Er

Flu

ores

cen

ce

wavelength, nm

ErSm

IEEE Journal of lightwave technology, accepted 1999 Fiber Stress Journal of Optics B: Quant. Semiclassic. Optics, accepted 1999 Hollow Fiber Journal of Non-crystalline Solids, accepted 1999 Erbium Fiber Journal of Non-crystalline Solids, accepted 1999 Erbium Fiber Optics Communications, Vol. 161, 25 1999 Hollow fiber Optics Communications, Vol. 159/1-3, 139 1999 Dispersion IEE Electronics Letters, Vol. 34, No. 19, pp1852-1853 1998 Annular EDF IEEE Journal of Lightwave Technology, Vol. 16, 285 1998 Fiber Coating



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Approach / Goal

Amplifier structure SimulationFiber, pump structure SNUSNU Amplifier TestTransmission penalty Integration

Tm, Ho, Yb, Nd doping SpectroscopyHeavy metal silica fiber KJISTKJIST ManufacturabilityDouble clad pump fiber Co-doping

WEDFASNU / Lucent

RamanSNU / Southampton

RE-DFAKJIST / Brown

Who could tell us about the target ? We can’t ..well, modest target will be 150nm bandwidth optical amplifier ..

Rather, we promise that we will be keep staying Rather, we promise that we will be keep staying as one of the world leaders !as one of the world leaders !



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Reminder : How much bandwidth?

Current technology cover only 10% of usable bandwidth

Nortel working on 100 Tera bps Ethernet routerLucent / JDS / Cronos / Xros working on 1000 x 1000 WDM channel optical switch

Lucent / Nortel / Corning / NEC working on Ultra-wideband amplifier

wherever the technology goes, we will trace, and will keep staying at the competitive edge

Wavelength (nm)1300 1400 1500 16000.0

0.1

0.2

0.3

0.4

Los

s (d

B/k

m)

SMF

C-EDFA L-EDFA

GS-TDFAS + -TDFA

Raman-Amp

WEDFA

TDFAs

OH-free Fiber

0. 3 dB / km fiber loss



next generation optical amplifier for 10 ’ s of tera-bps data transmission

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