SolitonSoliton Research at the Lightwave Research at the LightwaveCommunication Systems LaboratoryCommunication Systems Laboratory

Ken Demarest

Department of Electrical Engineering & Computer ScienceUniversity of Kansas

SummarySummary

• Introduction to optical solitons

• The KU soliton generator

• The KU recirculating loop

• Preliminary soliton transmission results

• Summary and suggestion for future work

OpticalOptical Solitons Solitons

An optical soliton is a short, high-amplitude an optical pulsethat does not spread as it propagates

t

t

tOrdinary PulesSoliton Pules

t

fiber

fiber

Inpu

t

Inpu

t

Out

put

Out

put

Linear,Linear, Dispersive Dispersive Fiber Fiber

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Inte

nsity

Inte

nsity

TimeFrequency

Lengt

h

Lengt

h

KerrKerr Effect and Chirp Effect and Chirp

Amplitude Profile Kerr Phase Instantaneous Frequency

Front Back

t →

t →

t →

Nonlinear,Nonlinear, Nondispersive Nondispersive fiber fiber

Inte

nsit

y

Inte

nsit

yTime

Frequency

Lengt

h

Lengt

h

Nonlinear Fiber with Positive Nonlinear Fiber with PositiveDispersionDispersion

Frequency

Inte

nsity

Inte

nsity

Time

Lengt

h

Lengt

h

FundamentalFundamental Soliton Soliton

.

Inte

nsit

y

Inte

nsit

yTime

Frequency

Lengt

h

Lengt

h

SolitonSoliton-based optical fiber-based optical fibertransmissiontransmission

Achieved error free distances in single-channel and WDM

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Title:soliton2.psCreator:XV Version 3.00 Rev: 3/30/93 - by John BradleyPreview:This EPS picture was not savedwith a preview included in it.Comment:This EPS picture will print to aPostScript printer, but not toother types of printers.

Three Types ofThree Types of Soliton Soliton Generators Generators

1. Soliton laser based on mode-locking

2. Electroabsorption Modulator-based soliton generators

3. LiNbO3 Mach-Zehnder Modulator-based solitongenerators

Mach-Mach-Zehnder SolitonZehnder Soliton Generator Generator

Amplitude ModulationAmplitude Modulation

Pulse CompressionPulse Compression

Structure and OperationStructure and OperationTitle:/tmp/xfig-fig015248Creator:fig2devPreview:This EPS picture was not savedwith a preview included in it.Comment:This EPS picture will print to aPostScript printer, but not toother types of printers.

KUKU Soliton Soliton Generator Generator

Uncompressed pulses Compressed pulses

MearsuredMearsured Pulse Compression Pulse Compression

SolitonSoliton Source: Output Source: Output

Soliton Train Data Encoded Soliton Sequence

20GHz Time/polarization Division20GHz Time/polarization DivisionMultiplexedMultiplexed Soliton Soliton Train Train

PM fiber

Incident LightPolarization of

SolitonSoliton Generator For WDM Generator For WDM

RecirculatingRecirculating Loop Loop

KUKU Recirculating Recirculating Loop Loop Testset Testset

OC48 Rate TransmissionOC48 Rate TransmissionEmulationEmulation

Standard Fiber

75 km: Error Free

600 km: Error Free(BER<2*10-13)

1050 km: BER=2*10-10

1350 km: BER=3*10-7

20 ps/divTransmitter

4*35 km

6*35 km

Launch power: 8 dBm -2.5 dBm

Measured, Near-Measured, Near-SolitonSolitonCharacteristicsCharacteristics

Future WorkFuture Work

1. Long-distance 10 Gb/s or time/polarization-division-multiplexedsoliton transmission in alternating positive and negative dispersionfiber links.

2. 10 Gb/s or 20 Gb/s WDM transmission in dispersion-compensated standard fiber link with long amplifier spans.

3. Experimental demonstration of soliton control for all-opticalnetworks.