new delivering 40gbps optical communication systems

Delivering 40GbpsDelivering 40Gbps OpticalOpticalCommunication SystemsCommunication Systems

Eldon Staggs, Steve Rousselle, and Daniel WuEldon Staggs, Steve Rousselle, and Daniel Wu

Agenda! Digital Communication System

! Fiber-Optic System Standards

! Single Channel System

!! ElectroElectro--Optical TransmitterOptical Transmitter

!! Optical FiberOptical Fiber

!! Optical DevicesOptical Devices

!! ElectroElectro--Optical ReceiverOptical Receiver

! Conclusions

Agenda! Digital Communication System

! Single Channel System

!! ElectroElectro--Optical TransmitterOptical Transmitter


!! Optical DevicesOptical Devices

!! ElectroElectro--Optical ReceiverOptical Receiver

! Conclusions

Digital Communication System

Bit/Symbol Stream Digital/Analog/Optical Waveform

Channel Encoder

Baseband Modulate Multiplex Transmitter

ChannelModel

ReceiverDe-Multiplex

Baseband Demodulate

Channel Decoder

N USERS

N USERS

Data Source

Data Sink

Synchronization

WaveformModulation

WaveformDe-

Modulation

Source Decoder

SourceEncoder

Digital Communication System

! Optical Communications System! Information encoded/decoded for pertinent protocol & modulation scheme! Multiple sets of data are combined/separated through TDM & WDM! Fiber Optic components provide the channel linking Transmitter to Receiver

N Users/ Wavelength

Video/ Audio/ Data

Enco

de

TDM

MU

XD

EMU

X

λm

Decode

λ1Optical Optical ChannelChannel

λm

λ1

TDM

Video/ Audio/ Data

Fiber Optic System Standards SectionFiber Optic System Standards Section

System Network!! Network ConnectivityNetwork Connectivity

! Point to Point: one to one! Broadcast: one to many! Multicast: many to many

!! Network SpanNetwork Span! Local / Metro Area Network! Wide Area Network! Long Haul Network

!! Data RatesData Rates! Voice 64kbps! Video 155Mbps, etc.

!! Service TypesService Types! Constant or Variable bit rate! Messaging! Quality of Service

OSI Reference Network Model

!! Open System Interconnection (OSI) Reference ModelOpen System Interconnection (OSI) Reference Model! Most systems use some form of OSI! L1: Physical & electrical elements! L2: Media access strategy! L3: Network maintenance (IP)! L4: Transport management (TCP)! L5: Link maintenance! L6: Format presentation! L7: Application link

!! Layers ModeledLayers Modeled! Physical (L1)! Medium Access (L2)

Fiber Optic System Standards

!! SonetSonet/SDH/SDH! Multiple data rates allowed! OC-x (x*51.84Mbps)! OC-768 = 40Gbps

!! FDDIFDDI! 100Mbps, Dual Token Ring

!! EthernetEthernet (IEEE802.3)! 10Mbps! High Speed (100Mbps)! Gigabit Ethernet

!! ATMATM! 53Byte packets! Connection oriented

SONET/SDH

!! Network ManagementNetwork Management! Path overhead! Combining multiple services! Centralized control

!! ProtectionProtection! Redundant Ring! Fast Error Detection! Synchronization

!! Bandwidth ManagementBandwidth Management! Multiplex all data rates! Scalability! Consolidation

NodeA

NodeC

NodeD

NodeB

Working Fibers

Backup Fibers

SONET/SDH

!! Network SimplificationNetwork Simplification! Access all signals! World wide standard! Component Reduction

!! MidMid--Fiber AccessFiber Access! Add/Drop Modules! Terminal Multiplexer! Cross-connects

SONET/SDH!! Signal CapacitiesSignal Capacities

! Non-Synchronous - Typically on copper! Synchronous - Intended for fiber

16 E42488.32STM1648 DS32488.32STS48/OC48

4 E4622.08STM412 DS3622.08STS12/OC12

1 E4155.52STM13 DS3155.52STS3/OC3

256 E439813.12STM256768 DS339813.12STS768/OC768

64 E49953.28STM64192 DS39953.28STS192/OC192

21 E151.84STM01 DS351.84STS1/OC1

Synchronous

7680 V564.992E54032 V274.176T4/DS4

1920 V139.264E4672 V44.736T3/DS3

480 V34.368E396 V6.312T2/DS2

120 V8.448E224 V1.544T1/DS1

30 V2.048E11 Voice(V)64kbpsDS0Non-Synchronous

ChannelsBit Rate [Mbps]

SignalChannelsBit Rate [Mbps]

Signal

ITU-T (Europe)ANSI (North America)

SONET

!! SONET STSSONET STS--1 Frame Structure1 Frame Structure! Transport Overhead! Path Overhead! Bit Rate vs Data Rate

⋅==

⋅⋅⋅==

BitsRowBitsDataRateBitMbpsRateData

bytebits

rowbytes

framerowsframesMbpsRateBit

_90_84_384.48_

8909sec

800084.51_

90 Columns (Bytes)

STS-1 SynchronousPayload Envelope

Tran

spor

tO

verh

ead

Path

Ove

rhea

d

9 R

ows (

Byt

es)

LineOverhead

SectionOverhead

86 Columns (Bytes)

125u

sec

SONET!! STSSTS--1 Synchronous Payload Envelope1 Synchronous Payload Envelope

! Virtual Tributaries / Groups! Pointers! Column Interleaving! STS-N Extensions

9 R

ows

Path

Ove

rhea

d

Stuf

fed

Bits

Stuf

fed

Bits

Virt

ual T

ribut

ary

Gro

up

84 Payload, 2 Stuffed, & 1 POH Column

12 Columns

Virt

ual T

ribut

ary

Virt

ual T

ribut

ary

Virt

ual T

ribut

ary

Virt

ual T

ribut

ary

Single Channel System SectionSingle Channel System Section

Single Channel System

!! Single ChannelSingle Channel! Prove ideal set up first! Establish system limitations! TDM & WDM extensions

!! SONET/SDHSONET/SDH! OC-768 (40Gbps)! Defines lower level OSI layers

!! Physical MediumPhysical Medium! 1550nm wavelength! Single Mode Fiber

Multiple Channel System

!! Wavelength Division MultiplexingWavelength Division Multiplexing! Multiple protocols can be combined on a single fiber! Throughput expansion with colors! Optical Traffic Control

! Add/Drop, Mux/Demux, etc.! Complex non-linear effects

! FWM, DFG, SRS, SBS, XGM and XPM

!! Time Division MultiplexingTime Division Multiplexing! Traditional Electrical systems! Combine users into time slots! Timing interference effects

! Aperture jitter, Intersymbol Interference, etc.

ElectroElectro--Optical Transmitter SectionOptical Transmitter Section

Electro-Optical Transmitter

!! Source EncodingSource Encoding

!! Channel EncodingChannel Encoding

!! Baseband ModulationBaseband Modulation

!! Baseband Filtering/Pulse ShapingBaseband Filtering/Pulse Shaping

!! Light Source GenerationLight Source Generation

!! Optical Carrier ModulationOptical Carrier Modulation

Source & Channel Encoding!! Source EncodingSource Encoding

! Sample information! Remove data redundancy! Frame data in SONET format! Pseudo-random binary output

for simulation

!! Channel EncodingChannel Encoding! Add controlled redundancy! Random Error Correction

! Block Codes! Convolutional Codes

! Burst Error Correction! Interleaving

Baseband Modulation!! Baseband ModulationBaseband Modulation

! Pulse Code Modulation! NRZ is standard optical format! RZ formatting

! Twice NRZ bandwidth! More tolerant to dispersion

! Duobinary coding! Half of NRZ bandwidth! Pre-coding stops error propagation

Baseband Modulation!! Duobinary with PreDuobinary with Pre--codingcoding

! XOR input w/past output! Output= XOR + past output! SNR performance down 4.77dB! Half of NRZ bandwidth! Decoding is simply mod2(signal)

NRZDuobinary

Baseband Modulation!! Polybinary CodingPolybinary Coding

! (Levels-2) memory elements! Smaller Bandwidth = NRZ/(L-2)

∑ −

=−=

−−⊕−⊕=2

0][][

)]2([]1[][][L

kknynz

Lnynynxny Κ

Baseband Filtering

!! Baseband FilteringBaseband Filtering! Spectral Containment! Pulse Shaping! RRCF, Gaussian, Sech, etc.

!! Modulator PreModulator Pre--conditioningconditioning! Scale signal prior to optical modulator

Optical Source

!! LEDLED! Low Power, Cost, Speed! Incoherent light! Line width (50-100nm)

!! LaserLaser! Coherent! Narrow spectral width (<8nm)! Temp. & Power control needed! Noise & Chirp

n-InP n-InGaAsP p-InP

1.35eV1.35eV

0.8eV

phph

hchEλ

υ ==

LASER Types

!! FabryFabry--Perot (FP)Perot (FP)! LED with mirrors! Index & Gain Guided! Multiple Modes! Spectral width (5-8nm)

!! Distributed Feedback (DFB)Distributed Feedback (DFB)! Internal Bragg Grating! Low noise & chirp! Narrow line width (50kHz)! Sensitive to Reflections & Temp.! High cost

Active Region

Active Region

⋅=Λ

nm ph

Bragg2λ

⋅=

nmL ph

cavity2λ

LASER Types!! Distributed Bragg Reflector (DBR)Distributed Bragg Reflector (DBR)

!! External Bragg GratingExternal Bragg Grating!! Same as DFBSame as DFB!! Temperature stabilityTemperature stability!! Very good, but high costVery good, but high cost

!! VCSELVCSEL!! Emits photons verticallyEmits photons vertically!! StableStable!! Low threshold current & power dissipation.Low threshold current & power dissipation.!! Good modulation bandwidthGood modulation bandwidth

!! QW & MQWQW & MQW! Cavity with very thin layer(s) (~10nm)! Low power requirements (high gain)! Narrow line width

Active Region

MQW Active Region

Electro-Optic Modulator

!! MachMach--Zehnder InterferometerZehnder Interferometer! Quadrature splitter/combiners! Differential Phase! Electro-Optic conversion

Electro-Optic Modulator!! MachMach--Zehnder Modulator DesignZehnder Modulator Design

! Broad-Band optical modulator with traveling-wave electrodes! The example shows a coplanar waveguide structure with an anisotropic LiNbO3 substrate

that exhibits a Pockels electro-optic effect! The electro-optic effect is the change in the refractive index caused by an applied

electric field! The Pockels effect refers to a material that changes its index of refraction linearly

with the applied electric field(E-Field)! Applying an E-Field to a length of Pockels material while an optical signal is

passed through it will result in an optical phase shift! An important parameter for optical modulators is the half-wave voltage(Vπ).

This is the applied voltage that results in an optical phase shift of π.

SiOSiOSiOSiO2222 Buffer LayerBuffer LayerBuffer LayerBuffer Layer

Electrode StructuresElectrode StructuresElectrode StructuresElectrode Structures

LiNbOLiNbOLiNbOLiNbO3333

Optical WaveguidesOptical WaveguidesOptical WaveguidesOptical Waveguides

ActiveActiveActiveActive

BendBendBendBend

TaperTaperTaperTaper

In/OutputIn/OutputIn/OutputIn/Output


!! ElectroElectro--Optical Modulator DesignOptical Modulator Design

! The design of the electrodes is critical for optimal performance! Speed of the modulator is limited by the electrical capacitive effects! Velocity of the Electrical and Optical signals must be matched! The length of the Active region or Interaction length is critical

! Demands precise modeling and control of Microwave propagation characteristics! Evaluation of Frequency dispersion for:

! Microwave effective index! Characteristic Impedance! Attenuation Constant

! Evaluation of Electrical performance for:! Finite electrode thickness and conductivity! Metalization undercutting! SiO2 buffer layer

Vector EVector EVector EVector E----Field PlotField PlotField PlotField Plot

Complex Magnitude of the Electric FieldComplex Magnitude of the Electric FieldComplex Magnitude of the Electric FieldComplex Magnitude of the Electric Field

Ansoft HFSS is used to calculate the Ansoft HFSS is used to calculate the Ansoft HFSS is used to calculate the Ansoft HFSS is used to calculate the Field Solution inside the conductorsField Solution inside the conductorsField Solution inside the conductorsField Solution inside the conductors


Fiber Optic Channel sectionFiber Optic Channel section

Fiber Optic Channel


! Fiber Types (SM, DSF, DCF)

! NLS Equation

! Dispersion Effects

! Nonlinear Effects

! Optimization

Optical Fiber!! Fiber TypesFiber Types

! Single Mode Fiber has energy centered in the core (LP01 mode)! Multi-Mode Fiber has a large core that support many propagation modes! DCF, DSF and NZDSF fibers types

!! Fiber ModesFiber Modes (See Appendix C for details)! Maxwell’s equations with variable permittivity! Electric field split into envelope and modal distributions! General Mode field distributions

!! Single mode conditionSingle mode condition

radiuscoreaknnakV

oo

o

_,/24.22

221

==<−⋅⋅=

λπ

yorxitzAi ),,( =z

)0,(zAi

waveformpulse period onefor ),( TzAi

t

),0( tAi

!! Electric FieldElectric Field! Envelope has polarization components! Anisotropic materials are Birefringent! Spatial, temporal, modal and

polarization dependent

zjjmiz eeFzArE βφρωω ⋅⋅⋅= ±)(),(),(

~

Field Envelope Description in Optical Fiber

z

Nonlinear Schrödinger(NLS) Equation

velocitygroupvgvgztztT

AT

ATAAT

jAAiTA

TAjA

zA

Ro

_,/

))(( 6 22

1

2223

33

2

2

2

=−=⋅−≡∂∂⋅⋅−

∂∂⋅+⋅=

∂∂⋅−

∂∂⋅⋅++

∂∂

βω

γββα

!! NLS Equation (Fiber Wave Propagation)NLS Equation (Fiber Wave Propagation)! Derived from Maxwell’s equations! Solve to find the envelope function versus time and distance! α is the attenuation factor! β1 is the inverse of the group velocity! β2 is the group velocity dispersion factor! β3 is the third order dispersion factor! γ is the self phase modulation factor! γ/ωo is the self-steepening factor! Tr is the Raman scattering factor

Fiber Attenuation

!! Fiber LossFiber Loss! Attenuation! SMF Loss = 0.2dB/km at 1550nm

α⋅⋅= )(log10]/[ 10 ekmdBLoss

Group Velocity Dispersion (GVD)

!! Pulse width spreadingPulse width spreading! Dispersion = -2*π*c*β2/λ2

! Dispersion Length! Ld = 31.25km for PW=25ps=1/40Gbps

2

2

2β

odTL =

Third Order Dispersion (TOD)

!! Dispersion Induced OscillationsDispersion Induced Oscillations! Only occurs when GVD is very small! TOD Oscillations! TOD Length! Ld3 = 156,250km for PW=25ps

3

3

3β

odTL =

Self Phase Modulation

Blue Shift

Red Shift

!! Spectral BroadeningSpectral Broadening! Increases with Power! Nonlinear Length! Induced FM Chirp

oNL

PL

⋅=

γ1

Fiber Distortion Summary

!! AttenuationAttenuation

!! DispersionDispersion! Chromatic (GVD & TOD)! Polarization (PMD)

!! Phase distortionPhase distortion! Self Phase (SPM)! Cross Phase (XPM)

!! Nonlinear Energy TransferNonlinear Energy Transfer! Acoustic (SBS)! Electromagnetic (SRS)

!! Four Wave MixingFour Wave Mixing

Fiber Channel Optimization!! Loss ManagementLoss Management

! EDFA / Repeater

!! Dispersion CompensationDispersion Compensation! Normal / Anomalous GVD! Dispersion Length

!! NonNon--Linear DistortionLinear Distortion! Effective NL length! Max Power! Channel Spacing

!! NoiseNoise! Filters / Isolators! Repeaters

oNLodod

PLTLTL

⋅===

γββ1,,

3

3

32

2

Optical Devices SectionOptical Devices Section

Optical Devices

!! Component TechnologyComponent Technology!! FiberFiber!! Planar WaveguidePlanar Waveguide

!! Optical Amplifier (EDFA)Optical Amplifier (EDFA)! Optical versus Electrical! Physical Mechanism! Amplifier Topology

!! Passive OpticalPassive Optical! Filters! Splitters/Couplers! OXCs/OADMs! Circulators/Isolators

Component Technology

!! Fiber TechnologyFiber Technology!! Common link mediumCommon link medium!! Minimal insertion lossMinimal insertion loss!! Large number of available devicesLarge number of available devices

!! Planar Waveguide TechnologyPlanar Waveguide Technology!! Embedded in substrateEmbedded in substrate!! Easily combine subEasily combine sub--componentscomponents!! Critical Dimension controlCritical Dimension control!! Difficulty in Fiber interfaceDifficulty in Fiber interface

Optical Amplifier

!! Erbium Doped Fiber Amplifier (EDFA)Erbium Doped Fiber Amplifier (EDFA)! Replace expensive electro-optic repeaters! Purely optical in 1525nm-1565nm range! Amplified Spontaneous Emission (ASE) - Noise! Pump wavelength of 980nm

Pump Laser980nm or 1490nm

Input Signal1.53µm-1.57µm

Amplified Output SignalErbium doped fiber

Optical Amplifier

!! Optical versus Electrical AmplifierOptical versus Electrical Amplifier! Gain saturation

! Soft relaxation time! Inter-Modulation Distortion

! Only electrical amps! Noise Figure

! NF = SNRin / SNRout! Interface issues

! Matching networks! Stability

! Optical Isolator at output! Electrical feedback

! Failure! Optical pass through! Electrical open

1525-1565nm

980n

m

1480

nm

τ ~ 10ms

Optical Filters!! FabryFabry--Perot FilterPerot Filter

! Cavity between reflectors! Finesse based on mirror R! FSR based on cavity length

!! MachMach--Zehnder FilterZehnder Filter! Delta path delay dictates periodicity! Cascaded filters provide greater

selectivity!! Noise Reduction & IsolationNoise Reduction & Isolation

Passive Optical Elements

!! Splitters / CouplersSplitters / Couplers! Signal monitoring! Broadcasting

!! OADMsOADMs//OXCsOXCs! Network link! Network switch

Coupling Length

Cores

Cladding

Gap

λ1

λ2

λ2

λ1

λ1

λ1, λ2,…

λ1a

λ1a, λ2,…

Passive Optical Elements

!! Circulators/IsolatorsCirculators/Isolators! Bi-directional system! Reflection suppression

!! InIn--Fiber Bragg GratingsFiber Bragg Gratings! Wavelength selector! Many configurations

! Filter! Dispersion Compensator! In-Fiber laser

Braggn Λ⋅= 2λ

Non-selectedwavelengths

Input Signal

Selected Wavelength

ElectroElectro--Optical Receiver SectionOptical Receiver Section

Electro-Optical Receiver!! PhotodetectorPhotodetector

! Convert optical power to electrical current! PIN / APD diode! Shot & Thermal Noise

!! TransTrans--Impedance AmplifierImpedance Amplifier! Convert current to voltage! Amplify small receiver signal

!! Packaging (BGA) & SubstratePackaging (BGA) & Substrate! Parasitic Effects! Coupling Effects

!! SynchronizationSynchronization! Normalize & Digitize! Clock/Data Recovery

!! Baseband DemodulationBaseband Demodulation

PhotoDetector

!! Optical Power ConversionOptical Power Conversion! Electrical current! PIN / APD Diodes

!! Diode DetectorsDiode Detectors! Dark Current! Responsivity [A/W]! Quantum Efficiency (η)

Wm eh

qR αµ ηηλυ

η −−=≈= 1,24.1

][

p-InP i-In.53Ga.47As n-InP

W +V

PhotoDetector

!! Diode Detectors (Cont’d)Diode Detectors (Cont’d)! Wavelength Range! Bandwidth

!! NoiseNoise! Thermal noise! Shot Noise! APD gain

CpRsRvWBW

LRCdrifttr

RCtr

)(,))(2/(1+==

+=ττ

ττπ

!! Functional ModelFunctional Model! Current Controlled Voltage Source! Feedback provides sensitivity! Feedback improves bandwidth! Amp gain improves response time

Trans-Impedance Amplifier

GainLoopOpenTTZZ ampinin __,/ =≈


!! TechnologyTechnology! Large Gain-Bandwidth product needed for 40Gbps! III-V HBTs (GaAs, InP) (fT = 250 GHz, fmax = 800 GHz)


!! Circuit ExampleCircuit Example! Thermal Modeling! Feedback & Bias

Feedback& Bias

Bias

SinkTemperature

ThermalResistance

!! TransTrans--Impedance GainImpedance Gain! Broadband


Trans-Impedance Amplifier & PIN Diode

Nonlinear model in Harmonica:

Term=106

PIN DiodeWith

Reverse Bias


!! Addition of PhotodiodeAddition of Photodiode! Reverse Bias! Bandwidth impact


!! TransTrans--Impedance GainImpedance Gain! Reactive matching

BGA Package design courtesy of ConnectCom MicroSystemsConnectCom MicroSystemsConnectCom MicroSystemsConnectCom MicroSystems Inc.

ConnectCom MicroSystemsConnectCom MicroSystemsConnectCom MicroSystemsConnectCom MicroSystems Inc. is a Venture Capital backed Internet Chip Company. It designs and manufactures ultra-low power, very high-speed analog and mixed-signal integrated circuits (ICs). These ICs enable and support terabit optical switching equipment and networks that form the new backbone infrastructure for the exploding Internet traffic.

ConnectComConnectComConnectComConnectCom employs innovative and patented designs techniques that are technology independent; to achieve power savings of up to 70% over traditional solutions for standards compliant SONET and SDH based applications. This will allow the company to offer superior, predictable economies, reliability and flexibility to the system designers of switch fabrics, DWDM equipment and optical modules.

CORPORATE OVERVIEWCORPORATE OVERVIEW

BGA: Critical Net Design! Ansoft HFSS, Full-Wave Spice, and Symphony provide

high-speed package designers the ability to characterize individual components or entire systems

! Full-Wave Spice and Symphony bridge the gap between frequency- and time-domain simulation

! Integration with industry standard layout tools provides a clean design flow from layout to analysis to production

ViaViaViaVia

Solder Solder Solder Solder BallsBallsBallsBalls

Ground Ground Ground Ground NetNetNetNet

Signal NetSignal NetSignal NetSignal Net

PowerPowerPowerPower

BGA: Design Integration

AnsoftLinksAnsoftLinksAnsoftLinksAnsoftLinks

3D Physical3D Physical3D Physical3D PhysicalModelModelModelModel

APDAPDAPDAPDAllegroAllegroAllegroAllegroEncoreEncoreEncoreEncoreZukenZukenZukenZuken

IGES, STEP, GDSII,IGES, STEP, GDSII,IGES, STEP, GDSII,IGES, STEP, GDSII,ACIS, DXF, AutoCADACIS, DXF, AutoCADACIS, DXF, AutoCADACIS, DXF, AutoCAD

Ansoft HFSSAnsoft HFSSAnsoft HFSSAnsoft HFSS

BGA: Simulation Results

BGA: Field Plots

Surface Current

E-Field on Surface of Core

BGA: Time-Domain Analysis

! Full-Wave Spice generates broad-band SPICE sub-circuits

! Supports Ansoft Maxwell Spice, PSPICE, or HSPICE

CrosstalkCrosstalkCrosstalkCrosstalkInput/OutputInput/OutputInput/OutputInput/Output

FullFullFullFull----Wave SpiceWave SpiceWave SpiceWave Spice

BGA: TDR Simulations

BGA:Eye Diagrams

BGA: BER

Signal Conditioning

!! AGC / LimiterAGC / Limiter! Normalize average gain variation! Protect follow on circuitry

!! Matched FilterMatched Filter! Digitize signal with ADC! Digital filter matched to transmitter! Minimizes out of band noise

Synchronization

!! Phase Lock LoopPhase Lock Loop! Pilot sequence! Over sample and detect edges! Provides data alignment

!! IntegrateIntegrate! Sum over a symbol period! Normalize output

Synchronization & Demodulation

!! Baseband DemodulationBaseband Demodulation! Invert the modulation scheme! Threshold detection for NRZ & RZ! Polybinary requires modulo-2

detection

Conclusions SectionConclusions Section

Conclusions!! System LimitationsSystem Limitations

! Loss Amplifier/Repeater stages! Dispersion DSF/DCF fiber use! Nonlinearity Unequal channel spacing! Noise Repeaters & Filters

!! Tools UsedTools Used! Symphony/Matlab System Level Simulation! Harmonica Circuit Level Simulation! HFSS Physical Level Simulation

!! System OptimizationSystem Optimization! Simulation needed for practical realization! Break design into smaller pieces

Appendix A (Acronyms)Appendix A (Acronyms)!! ADMADM Add-Drop Module!! AGCAGC Automatic Gain Control!! AMAM Amplitude Modulation!! APDAPD Avalanche Photodiode!! ASEASE Amplified Spontaneous Emission!! ATMATM Asynchronous Transfer Mode!! BERBER Bit Error Rate!! BGABGA Ball Grid Array!! BJTBJT Bipolar Junction Transistor!! CDRCDR Clock/Data Recovery!! CSMACSMA Carrier-Sense Multiple Access!! CWCW Continuous Wave!! DBRDBR Distributed Bragg Reflector!! DCFDCF Dispersion Compensating Fiber!! DFBDFB Distributed Feedback!! DFGDFG Difference Frequency Generation

!! DSFDSF Dispersion Shifted Fiber!! DWDMDWDM Dense Wavelength Division Multiplexing!! EDFAEDFA Erbium Doped Fiber Amplifier!! FDDIFDDI Fiber Distributed Data Interface!! FETFET Field Effect Transistor!! FPFP Fabry-Perot!! FSRFSR Free Spectral Range (Channel Spacing)!! FWHMFWHM Full Width at Half Maximum (3dB BW)!! FWMFWM Four Wave Mixing!! GVDGVD Group Velocity Dispersion!! HBTHBT Heterojunction Bipolar Transistor!! IPIP Internet Protocol!! ISIISI Inter-Symbol Interference!! LANLAN Local Area Network!! LASERLASER Light Amplified Stimulated Emission of

Radiation!! LEDLED Light Emitting Diode!! MANMAN Metropolitan Area Network

Appendix A (Acronyms)Appendix A (Acronyms)!! MZMZ Mach-Zehnder!! MMFMMF Multi-Mode Fiber!! MQWMQW Multi-Quantum Well!! NLSNLS Non-Linear Schrödinger Equation!! NRZNRZ Non-Return to Zero!! NZDSFNZDSF Nonzero Dispersion Shifted Fiber!! OCOC Optical Carrier!! OXCOXC Optical Cross-Connect!! PCMPCM Pulse Code Modulation!! PINPIN p-i-n semiconductor !! PLLPLL Phase Locked Loop!! PMDPMD Polarization Mode Dispersion!! RZRZ Return to Zero!! SBSSBS Stimulated Brillouin Scattering!! SDHSDH Synchronous Digital Hierarchy!! SINADSINAD Signal-to-Noise and Distortion!! SMFSMF Single Mode Fiber

!! SNRSNR Signal-to-Noise Ratio!! SONETSONET Synchronous Optical Network!! SPMSPM Self Phase Modulation!! SRSSRS Stimulated Raman Scattering!! STMSTM Synchronous Transport Module!! STSSTS Synchronous Transport Signals!! TCPTCP Transfer Control Protocol!! TDMTDM Time Division Multiplexing!! TIATIA Transfer-Impedance Amplifier!! TODTOD Third Order Dispersion!! VCSELVCSEL Vertical Cavity Surface Emitting Laser!! VTVT Virtual Tributary!! WANWAN Wide Area Network!! WDMWDM Wavelength Division Multiplexing!! XGMXGM Cross Gain Modulation!! XPMXPM Cross Phase Modulation

Appendix B (Protocol Details)Appendix B (Protocol Details)

Fiber Distributed Data Interface

! FDDI (ANSI X3T12)! Dual Token Ring, Opposite directions! 4B/5B NRZ Encoding! 100Mbps = 125Mbaud*(4/5)

Ethernet

!! Ethernet (Ethernet (IEEE802.3IEEE802.3))! CSMA/CD scheme! 10Mbps (10Base-FL)! 100Mbps (100Base-FX)! 1Gbps (1000Base-SX,LX)

!! OSI LayersOSI Layers! MAC & PHY (no LLC)

!! Frame FormatFrame Format

Preamble DestAddr

SourceAddr Type Payload Postamble

Asynchronous Transfer Mode

!! Asynchronous Transfer Mode (ATM)Asynchronous Transfer Mode (ATM)! 53 Byte cells (48 Byte data sets = AAL + Data)! Service types: CBR, CVR and Data! Virtual Channels / Virtual Paths

Data + AAL(48B)

Header (5B)

UNI Header NNI Header

VCI

HEC

GFC VPI

VCI PT CLP

VPI VCI

VCI

HEC

VPI

VCI PT CLP

VPI VCI

Asynchronous Transfer Mode

!! ATM Adaptation LayerATM Adaptation Layer! AAL1 – Constant Bit Rate! AAL2 – Variable Bit Rate! AAL3/4 – Connection & Connectionless! AAL5 – IP Packets & Other

AAL1

AAL3/4

AAL2

AAL5 SAR-SDU (43B=344b)

ST(4b)

SN(4b)

RES/MID(10b)

SAR-SDU CRC(10b)

LI(6b)

SN(4b)

IT(4b)

SAR-SDU CRC(10b)

LI(6b)

SN(4b)

SNP(4b)

SAR-SDU

SAR-SDU = Data

Appendix C (Fiber Model Derivations)Appendix C (Fiber Model Derivations)

Nonlinear SchrÖdinger (NLS) Equation

iablevarcomplextE

cE

tEBB

tE

BDtDH

tBE

JFiberinAssume

BDtDJH

tBE

EquationssMaxwellEquationssMaxwellfromNLSofDerivation

rr

roo

_,

,

0,0,,

0,0:__

0,,,

:_'_'_____

2

2

22 =

∂∂⋅=∇

∂∂⋅⋅⋅=×∇×∇

∂∂−=×∇×∇

=⋅∇=⋅∇∂∂=×∇

∂∂−=×∇

==

=⋅∇=⋅∇∂∂+=×∇

∂∂−=×∇

εε

εωω

ωωωω

ωωωωωω

ω

ωωωωωωω

εµ

ρ

ρ


Quoted from “Nonlinear Fiber Optics” by Govind P. Agrawal

zjjm

m

m

zjjm

ooorr

eeFzAE

knknaKbaJb

F

eZeenvelopepulseyingslowlyzA

zZFzAEsCoordinatelCylindricainiablesofseparationUse

kEkEEc

E

domainfrequencyinSolve

βφ

βφ

ρω

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Appendix D (References)Appendix D (References)! Nonlinear Fiber Optics, 3rd Edition, Govind Agrawal

! Fiber-Optic Communication Systems, 2nd Edition, Govind Agrawal

! Digital Communications, Bernard Sklar

! Mathematical Methods for Physicists, 3rd Edition, Arfken

! Understanding Optical Communications, IBM Redbook, Harry Dutton

! Synchronous Optical Network, Tektronix App. Note

! Electronic Circuit Analysis, Colclaser, Neaman & Hawkins

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