optical fiber transmission amplifications for ultra long haul applications

8/20/2019 Optical Fiber Transmission Amplifications for Ultra Long Haul Applications

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177International Journal of Scientific Research Engineering & Technology (IJSRET), ISSN 2278 – 0882

Volume 3 Issue 2, May 2014

Where λ s and λ p are the signal and pump wavelengths in

µm respectively, z is the distance in km from z=0 to z=L,

Ls and Lp are the linear attenuation coefficient of thesignal and pump power in the optical fiber in km

-1

respectively. Equation (1) can be solved when both sidesof the equation are integrated. When using forward

pumping, the pump power can be expressed as the

following expression [10]: zP zP Lp poF PF α exp (3)

where PPoF is the input pump power in the forward

direction in watt at z=0. If the values of PP are substituted

in differential Eq. 2, and is integrated from z=0 to z=L for

the signal power in the forward, then the result

mathematical equation can be written as mentioned in

[10]:

z LP

A

gP zP Lseff po

eff

RsoS αexp (4)

where Pso and P po denotes to the input signal and pump

power respectively. This means that P po= P poF in case of forward pump and P po=P poB in case of backward pump,

and Leff , is the effective length in km, over which the

nonlinearities still holds or stimulated Raman scattering

(SRS) occurs in the fiber and is defined as [11]:

Lp

Lpeff

z L

α

α

exp1(5)

Recently, there have been many efforts to utilize fiber

Raman amplifier (FRA) in long-distance, high capacity

WDM systems. The net gain [12] is one of the most

significant parameters of the FRA. It describes the signal

power increase in the end of the transmission span and

presents the ratio between the amplifier accumulated gain

and the signal loss. It can be simply described by theexpression:

,)0(

)(

S

S net

P

zPG (6)

The intensity of the stimulated scattered light grows

exponentially once the incident pump power exceeds a

certain threshold value. The threshold pump power Pth isdefined as the incident power at which half of the pump

power is transferred to the Stokes field at the output end

of a fiber of length L. The threshold pump power satisfies

the condition [13]:

ff eff th

g L

PRe

16 , (7)

For standard silica cable fiber, the transmitted signal

bandwidth per transmitted channel can be given by [14]:

,4848.0

. z N

W Bch

sigτ

(8)

Where Nch is the number of transmitted channels, τ is the

total pulse broadening after distance z which is given by

[15]:

z D λτ , (9)

Where D is the total dispersion coefficient in fiber link media in ps/nm.km, and Δλ is the spectral linewidth of

the optical source. This is mainly because FRA can

improve the optical signal to noise ratio (OSNR) andreduce the impacts of fiber nonlinearities [16], that is the

OSNR of the system after amplification can be:

.10

.2

)(log10

Sig

S dB

W Bch

zPOSNR

λ , (10)

Where h is the Planck’s constant (6.02 x10-34

J.sec), PS (z)is the transmitted signal power after z distance, c is the

speed of light (3x108

m/sec), λ is the operating signal

wavelength in μm, and B.Wsig is the transmitted signal

bandwidth. According to modified Shannon theorem, themaximum bit rate per optical channel for supported

number of users, or the maximum capacity of the channelfor maximum subscribers is given by [17]:

,1log. 2 OSNRW B B sigSh (11)

Based on MATLAB curve fitting program, the

relationship between the signal quality factor (Q) with

both number of transmitted channels (Nch) and effective

length Leff in km and transmitted signal power after distance z can be expressed as the following formula:

)(5.18778.254.12

65.283322

zP L N L N L N

Q S

eff cheff cheff ch

,dB(12)

Then the bit error rate (BER) can be expressed as a

function of Q in the following formula [18]:

,8

exp..

2

Q

Q BER

π(13)

III. Results and Performance AnalysisThe optical FRAs have been modeled and have been

parametrically investigated in different fiber cable medias

such as true wave reach fiber, non return to zero

dispersion shifted fiber (NZ-DSF), and single mode fiber

(SMF) with employing different multiplexing techniques

namely ultra wide wavelength division multiplexing

(UW-WDM) based on the coupled differential equationsof first order, and also based on the set of the assumed of

affecting operating parameters on the system model. In

fact, the employed software computed the variables under

the following operating parameters as shown in Table 1.

Table 1. Proposed operating parameters for performance

signature of Raman amplifiers [3, 5, 12, 18].Operating

parameter

Symbol Value and unit

Operating signalwavelength

λ s 1.3 μm

Operating pump

wavelength

λ p 1.28 μm

Input signal

wavelength

PSo 10 dBm

Input pump power P po 30 dBm

Forward pump

ratio

r f 0.5

Signal attenuation αs 0.25 dB/km

Pump attenuation α p 0.3 dB/km

Spectral linewidth

of optical source

Δλ 0.1 nm

UW-WDMchannels

Nch(UW-

WDM)

10000 channels

Transmission

distance

z 0 ≤ z, km ≤ 400

Types of fiber cable media True wavereach fiber

NZ-DSF SMF

Effective area Aeff 55 μm2 72 μm2 85 μm2

Raman gain

efficiency

gReff 0.6 W-

1

km-1

0.45 W-

1

km-1

0.38 W-

1

km-1

Dispersion

coefficient

D 25

ps/nm.km

20

ps/nm.km

16

ps/nm.km



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Then the set of the series of the following figures are

shown below as the following can be obtained:

i) Fig. (1, 2) have assured that transmitted signal power and pump power decrease with increasing

transmission distance. It is observed that true wave

reach fiber has presented transmitted signal and

pump powers with compared other transmission

mediums.ii)Fig. (3, 4) have assured that signal gain and

threshold pump power decrease with increasing

transmission distance. It is observed that true wave

reach fiber has presented transmitted signal gain

and threshold pump power with compared other transmission mediums.

iii) Fig. 5 has indicated that transmitted signal

bandwidth decreases with increasing transmission

distance. It is theoretically found that single mode

fiber medium has presented the highest transmittedsignal bandwidth with compared to other

transmission fiber mediums.

0

2

4

6

8

10

12

14

0 50 100 150 200 250 300 350 400

True wave reach fiber

NZ-DSF

SMF

Transmission distance, Z, km

Fig. 1. Variations of transmitted signal power against variations of transmission distance at the assumed set of the operating

parameters.

0

2.5

5

7.5

10

12.5

15

17.5

20

22.5

25

27.5

30

0 50 100 150 200 250 300 350 400


NZ-DSF

SMF


Fig. 2. Variations of pump power against variations of transmission distance at the assumed set of the operating parameters.

T r a n s m i t t e d s i g n a l p o w e r , P s ,

d B m

P u m p p o w e r , P p , d B m



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5

10

15

20

25

30

35

40

0 50 100 150 200 250 300 350 400


NZ-DSF

SMF


Fig. 3. Signal gain in relation to transmission distance at the assumed set of the operating parameters.

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

0 50 100 150 200 250 300 350 400


NZ-DSF

SMF


Fig. 4. Threshold pump power in relation to transmission distance at the assumed set of the operating parameters.

0

100

200

300

400

500

600

700

800

900

1000

0 50 100 150 200 250 300 350 400


NZ-DSF

SMF


Fig. 5. Transmitted signal bandwidth in relation to transmission distance at the assumed set of the operating parameters.

S i g n a l g a i n , G d B

T h r e s h o l d p u m p p o w e r , P t h d B m

T r a n s m i t t e d s i g n a l b a n d w i d t h , B W s i g . ,

G H z



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0

5

10

15

20

25

30

35

0 50 100 150 200 250 300 350 400


NZ-DSF

SMF


Fig. 6. Optical signal to noise ratio in relation to transmission distance at the assumed set of the operating parameters.

10

20

30

40

50

60

70

80

90

0 50 100 150 200 250 300 350 400


NZ-DSF

SMF


Fig. 7. Shannon transmission bit rate in relation to transmission distance at the assumed set of the operating parameters.

5

10

15

20

25

30

35

40

0 50 100 150 200 250 300 350 400


NZ-DSF

SMF


Fig. 8. Signal transmission quality in relation to transmission distance at the assumed set of the operating parameters.

O p t i c a l s i g n a l t o n o i s e r a t i o , O S N R , d B

S h a n n o n t r a n s m i s s i o n b i t r a t e , B S h , T b / s

S i g n a l t r a n s m i s s i o n q u a l i t y , Q , d B



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0

1

2

3

4

5

6

7

8

9

10

0 50 100 150 200 250 300 350 400


NZ-DSF

SMF


Fig. 9. Signal bit error rate in relation to transmission distance at the assumed set of the operating parameters.

iv) Fig. 6 has indicated that optical signal to noise ratio increases with increasing transmission distance. It is

theoretically found that true wave reach fiber medium has presented the highest optical signal to noise ratio withcompared to other transmission fiber mediums.

v) Fig. 7 has assured that Shannon transmission bit

rate decreases with increasing transmission

distance. It is observed that single mode fiber has

presented the highest transmitted signal bit rate

with compared other transmission mediums.vi) Fig. 8 has indicated that signal transmission

quality decreases with increasing transmission

distance. It is theoretically found that true wave

reach fiber medium has presented the highest

signal transmission quality with compared to other

transmission fiber mediums.

vii) Fig. 9 has indicated that signal transmission bit

rate increases with increasing transmission

distance. It is theoretically found that true wave

reach fiber medium has presented the lowest signal

transmission bit rate with compared to other transmission fiber mediums.

IV. ConclusionsIn a summary, the model has been investigated

forward pumping based fiber optical Raman amplifiers in

different optical fiber transmission medium systems over

wide range of the affecting parameters. It is observed thattransmitted signal power, pump power and its threshold

value, signal gain, optical signal to noise ratio,

transmitted signal bandwidth, signal transmission quality

and transmission bit rates decrease with increasing

transmission distance. As well as true wave reach fiber

has presented the highest systems transmission performance compared to other transmission fiber

mediums under the same operating of conditions.

REFERENCES[1] Ahmed Nabih Zaki Rashed, Abd El-Naser A. Mohammed,

Mohamed M. E. El-Halawany, and Mohamoud M. Eid

“Optical Add Drop Multiplexers with UW-DWDMTechnique in Metro Optical Access Communication

Networks,” Nonlinear Optics and Quantum Optics, Vol.

44, No. 1, pp. 25–39, 2012.[2] Ahmed Nabih Zaki Rashed, Abd El-Naser A. Mohammed,

Mohamed M. E. El-Halawany, and Mohammed S. F.Tabour “High Transmission Performance of Radio over Fiber Systems over Traditional Optical Fiber

Communication Systems Using Different Coding Formatsfor Long Haul Applications,” Nonlinear Optics andQuantum Optics, Vol. 44, No. 1, pp. 41–63, 2012.

[3] Ch. Headley, G. Agrawal, “Raman Amplification in Fiber

Optical Communication Systems”, Elsevier, 2009.

[4] M. Islam, “Raman Amplifiers for Telecommunications andPhysical Principles”, Springer, 2004.

[5] L. Binh, T. Lhuynh, S. Sargent, A. Kirpalani, “Fiber Raman

Amplification in Ultra-high Speed Ultra-long HaulTransmission: Gain Profile, Noises and Transmission

Performance”, Technical Report MECSE-1-2007, CTIE,Monash University, 2007.

[6] H. B. Sharma1,T. Gulati, and B. Rawat, “Evaluation of Optical Amplifiers,” International Journal of EngineeringResearch and Applications (IJERA), Vol. 2, No. 1, pp. pp.663-667, 2012.

[7] Q. Hen, J. Ning, H. Zhang, and Z. Chen, “Novel ShootingAlgorithm for Highly Efficient Analysis of Fiber RamanAmplifiers,” IEEE J. Lightwave Technol., Vol. 24, No. 4,

pp. 1946-1952, 2006.[8] Abd El-Naser A. Mohammed, Abd El-Fattah Saad, Ahmed

Nabih Zaki Rashed, and Hazem Hageen “Low

Performance Characteristics of Optical Laser DiodeSources Based on NRZ Coding Formats under Thermal

Irradiated Environments,” International Journal of Computer Science and Telecommunications (IJCST), Vol.2, No. 2, pp. 20-30, 2011.

[9] M. N. Islam, “Raman Amplifiers for Telecommunications,”

IEEE J. of Select. Topics in Quantum Electron., Vol. 8,

No. 3, pp. 548–559, 2008.[10] A. Galtarossa, L. Palmieri, M. Santagiustina, and L. Ursini,

“Polarized Backward Raman Amplification in RandomlyBirefringent Fibers,” J. Lightwave Technol., Vol. 24, No.

3, pp. 4055–4063, 2009.[11] Abd El Naser A. Mohammed, Osama S. Fragallah, Ahmed

Nabih Zaki Rashed, and Mohamed El-Abyad, “NewTrends of Multiplexing Techniques Based Submarine

S i g n a l b i t e r r o r r a t e

, B E R x 1 0 - 1 2



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Optical Transmission Links for High TransmissionCapacity Computing Network Systems,” Canadian Journalon Science and Engineering Mathematics, Vol. 3, No. 3,

pp. 112-126, 2012.[12] X. Liu, J. Chen, C. Lu, and X. Zhou, “Optimizing Gain

Profile and Noise Performance for Distributed Fiber Raman Amplifiers,” Opt. Express, Vol. 12, No. 24, pp.

6053–6066, 2011.

[13] G. P. Agrawal, Fiber Optical Communication Systems, New York, John Wiley and Sons, 2005.

[14] I. Mandelbaum, M. Bolshtyansky, “Raman Amplifier

Model in Single Mode Optical Fiber,” IEEE Photon.

Technol. Lett., Vol. 15, No. 12, pp. 1704– 1706, 2009.[15] Abd El–Naser A. Mohamed, Ahmed Nabih Zaki Rashed,

and Amina El-Nabawy, “The Effects of the Bad Weather

on the Transmission and Performance Efficiency of OpticalWireless Communication Systems,” Canadian Journal onElectrical ad Electronics Engineering, Vol. 3, No, 5, pp.

209-224, May 2012.

[16] S. Hu, H. Zhang and Y. Guo, “Stiffness Analysis in the Numerical Solution of Raman Amplifier PropagationEquations”, Opt. Exp., Vol. 12, No. 2, pp. 1656-1664,

2010.[17] S. Kumar, and H. Singh, “Transmission Performance

64×10 Gb/s WDM System Based on Optical HybridAmplifiers Using RZ- Soliton Modulation Format atDifferent Transmission Distance,” IOSR Journal of

Engineering, Vol. 2, No. 7, pp. 7-12, July 2012.[18] Ahmed Nabih Zaki Rashed, Abd El–Naser A. Mohamed,

Sakr A. S. Hanafy, and Amira I. M. Bendary “Electrooptic

Polymer Modulators Performance Improvement With

Pulse Code Modulation Scheme in Modern OpticalCommunication Networks,” International Journal of Computer Science and Telecommunications (IJCST), Vol.2, No. 6, pp. 30-39, 2011.

Author’s Profile

Dr. Ahmed Nabih Zaki Rashed was

born in Menouf city, Menoufia State,

Egypt country in 23 July, 1976.Received the B.Sc., M.Sc., and Ph.D.

scientific degrees in the Electronics and

Electrical Communications Engineering

Department from Faculty of Electronic

Engineering, Menoufia University in

1999, 2005, and 2010 respectively.

Currently, his job carrier is a scientific lecturer in

Electronics and Electrical Communications Engineering

Department, Faculty of Electronic Engineering, Menoufia

university, Menouf. Postal Menouf city code: 32951,EGYPT. His scientific master science thesis has focused

on polymer fibers in optical access communicationsystems. Moreover his scientific Ph. D. thesis has focused

on recent applications in linear or nonlinear passive or

active in optical networks. His interesting research mainly

focuses on transmission capacity, a data rate product and

long transmission distances of passive and active optical

communication networks, wireless communication, radio

over fiber communication systems, and optical network

security and management. He has published many high

scientific research papers in high quality and technical

international journals in the field of advanced

communication systems, optoelectronic devices, and passive optical access communication networks. His areas

of interest and experience in optical communication

systems, advanced optical communication networks,

wireless optical access networks, analog communication

systems, optical filters and Sensors, digitalcommunication systems, optoelectronics devices, and

advanced material science, network management systems,

multimedia data base, network security, encryption and

optical access computing systems. As well as he is

editorial board member in high academic scientificInternational research Journals. Moreover he is a reviewer

member and editorial board member in high impact

scientific research international journals in the field of

electronics, electrical communication systems,

optoelectronics, information technology and advanced

optical communication systems and networks. His

personal electronic mail ID (E-mail:[email protected]). His published paper

under the title "High reliability optical interconnections

for short range applications in high speed optical

communication systems" has achieved most popular

download articles in Optics and Laser Technology

Journal, Elsevier Publisher in year 2013.

optical fiber transmission amplifications for ultra long haul applications

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