Optical Interconnect

8/3/2019 Optical Interconnect

1/19

Optical Interconnect andOptical Interconnect and

SensingSensing

Dr. How T. LinDr. How T. Lin

Endicott InterconnectEndicott InterconnectTechnologiesTechnologies

TopicsTopics

Light FundamentalsLight Fundamentals

Common Optical Components for Light Emission andCommon Optical Components for Light Emission andDetection and TransmissionDetection and Transmission

Optical Interconnect PrincipleOptical Interconnect Principle

Optical InterconnectsOptical Interconnects Fiber OpticsFiber Optics

Optical WaveguidesOptical Waveguides

Optical Sensing with FBG (Fiber Bragg Grating Sensing)Optical Sensing with FBG (Fiber Bragg Grating Sensing) PrinciplePrinciple

ApplicationsApplications

Disadvantages of ElectricalDisadvantages of Electrical

Interconnects/SensorsInterconnects/Sensors

Physical Problems (at high frequencies/highPhysical Problems (at high frequencies/highnoise environments)noise environments) CrossCross--talktalk

Signal DistortionSignal Distortion

Electromagnetic InterferenceElectromagnetic Interference

ReflectionsReflections

High Power ConsumptionHigh Power Consumption

High Latency (RC Delay)High Latency (RC Delay)

Limited BandwidthLimited Bandwidth

Why Optics ?Why Optics ?

Advantages:Advantages:

Capable to provide high bandwidthsCapable to provide high bandwidths

Free from electrical shortFree from electrical short--circuitscircuits

LowLow--loss transmission at high frequenciesloss transmission at high frequencies

Immune to electromagnetic interferenceImmune to electromagnetic interference

Essentially no crosstalk between adjacent signalsEssentially no crosstalk between adjacent signals No impedance matching requiredNo impedance matching required

Successful longSuccessful long--haul telecommunication system basedhaul telecommunication system based

on fiber opticson fiber optics


2/19

Using Lightwave to TransmitUsing Lightwave to Transmit

InformationInformationSimplified phasor representation of EM wave

E(t) cos(t+)

Amplitude frequency phase

Device a method to detect change in any

one of the three variables listedabove.we have a data transmitter!

Optical Interconnect FundamentalsOptical Interconnect Fundamentals

1 1

Basic Optical Interconnect

Transmitter Transmission Medium Receiver

Transmitter: LED or Laser

Transmission Medium: Fiber optics (MM/SM), Polymer Waveguide or Free Space

Receiver: Photo Diode or Transistor

EM SpectrumEM SpectrumEM Spectrum (Visible)EM Spectrum (Visible)

UV....VisibleIR


3/19

What is Light?What is Light?RaysWavesParticles

Absorption

Emission

Interference Refraction

Reflection

Bandgap

Conduction band

Valence band

n0

n1

n0

A little Quantum TheoryA little Quantum Theory Definition:Definition:

Optical powerOptical powerwatt (W)watt (W) -- a rate of energy of onea rate of energy of onejoule (J) per second.joule (J) per second.

Optical power is a function of both the number ofOptical power is a function of both the number ofphotons and the wavelength. Each photon carriesphotons and the wavelength. Each photon carriesan energy that is described by Planckan energy that is described by Plancks equation:s equation:

Q =Q = hchc//wherewhere Q= photon energy in JQ= photon energy in J

h = Planckh = Plancks constant (6.623 x 10s constant (6.623 x 10--3434 Js)Js)

c = speed of light (2.998 X x 10c = speed of light (2.998 X x 1088 m/sm/s))

= wavelength in meters= wavelength in meters

Basic Optical PrinciplesBasic Optical Principles

Optical FilterOptical Filter::

Absorption by filter glass variesAbsorption by filter glass varies

withwith and thickness (d) ofand thickness (d) of

substratesubstrate

At each interface, part of theAt each interface, part of the

incident light will be reflectedincident light will be reflected

and the rest will pass throughand the rest will pass through..

Interface LossesInterface Losses ::

FresnelFresnels Laws Law

rr = reflection loss (normal= reflection loss (normal

incidence)incidence)

nn == nn/n/n

rr == nn --1/1/ nn +1+1

Transmission through an optical filter

Interface Losses


RefractionRefraction ::SnellSnells Laws Law

n sin(n sin() = n) = n sin(sin())

Index of refraction:Index of refraction: n = 1.0 for airn = 1.0 for air

n = 1.5 for glassn = 1.5 for glass

Transmission through an optical filter


4/19

Basic Optical PrinciplesBasic Optical Principles DiffractionDiffraction::

Lightwave bends when pass by small apertureLightwave bends when pass by small aperture

= / = /DD

wherewhere is the diffraction angleis the diffraction angle

is the wavelengthis the wavelength

D is the aperture widthD is the aperture width

D

Basic Optical PrinciplesBasic Optical Principles InterferenceInterference::

Wave nature of light causes interference patterns:Wave nature of light causes interference patterns:

Interference filter for wavelength selectionInterference filter for wavelength selection --


CollimationCollimation:: Place point source at focal point of lens or parabolic mirrorPlace point source at focal point of lens or parabolic mirror

can produce collimated light (parallel light beam)can produce collimated light (parallel light beam)

Collimation with lens and parabolic mirror

Slit

Wavelength Selection:Wavelength Selection:

Prisms:Prisms:

with high n, selectwith high n, select withwith

narrow slitnarrow slit

Gratings:Gratings: disperse light intodisperse light into

spectrum with ruled linesspectrum with ruled lines

where m is an integerwhere m is an integer

(order)(order)



5/19

LasersLasers GasGas

LiquidLiquid

Solid StateSolid State

Semiconductor (diodes)Semiconductor (diodes)

Light Emitting Diodes (LED)Light Emitting Diodes (LED)

Light SourcesLight Sources LasersLasers((LLightight AAmplification bymplification by SStimulatedtimulated EEmission ofmission ofRRadiation)adiation) GasGas

Solid StateSolid State

LiquidLiquid

Semiconductor (diode)Semiconductor (diode)

Characteristics:Characteristics:

CoherenceCoherence -- Photons have fixed phase relationship.Photons have fixed phase relationship. Relative narrow spectraRelative narrow spectra

Low divergence after collimation.Low divergence after collimation.

Difficult to modulate (gas, liquid).Difficult to modulate (gas, liquid).

High cost.High cost.

LEDLED

((LLightight EEmittingmitting DDiodes)iodes)

Characteristics:Characteristics: IncoherenceIncoherence --Photons with random phasePhotons with random phase

Relative broad spectra.Relative broad spectra.

Low cost.Low cost.

Easy modulation.Easy modulation. Small sizeSmall size

Light SourcesLight Sources

Light Sources : Semiconductor LasersLight Sources : Semiconductor Lasers

active

n-DBR

p-DBR

VCSEL

Light Sources :Light Sources : LEDsLEDs

Edge emitting LED

Surface emitting LED


6/19

Light DetectionLight Detection Two broad classes of optical detectors:Two broad classes of optical detectors:

Photon detectorsPhoton detectors interactions of quanta of light energy with electrons ininteractions of quanta of light energy with electrons in

the detector material and generating free electrons (wavelengththe detector material and generating free electrons (wavelength

dependent).dependent).

Thermal detectorsThermal detectors -- respond to the heat energy delivered by the lightrespond to the heat energy delivered by the light

(wavelength independent).(wavelength independent).

Light DetectionLight Detection Photon detectors:Photon detectors:

PhotoemissivePhotoemissive. These detectors use the photoelectric effect, in. These detectors use the photoelectric effect, inwhich incident photons free electrons from the surface of thewhich incident photons free electrons from the surface of thedetector material. These devices include vacuum photodiodes,detector material. These devices include vacuum photodiodes,CCD camera, bipolar phototubes, and photomultiplier tubes.CCD camera, bipolar phototubes, and photomultiplier tubes.

Photoconductive. The electrical conductivity of the materialPhotoconductive. The electrical conductivity of the materialchanges as a function of the intensity of the incident light.changes as a function of the intensity of the incident light.Photoconductive detectors are semiconductor materials. TheyPhotoconductive detectors are semiconductor materials. Theyhave an external electrical bias voltage.have an external electrical bias voltage.

Photovoltaic. These detectors contain aPhotovoltaic. These detectors contain a pp--nn semiconductorsemiconductorjunction and are often called photodiodes. A voltage is selfjunction and are often called photodiodes. A voltage is selfgenerated as radiant energy strikes the device. The photovoltaicgenerated as radiant energy strikes the device. The photovoltaicdetector may operate without external bias voltage. A gooddetector may operate without external bias voltage. A goodexample is the solar cell used on spacecraft and satellites toexample is the solar cell used on spacecraft and satellites toconvert the sunconvert the suns light into useful electrical power.s light into useful electrical power.

Photoconductive and photovoltaic detectors are commonly used inPhotoconductive and photovoltaic detectors are commonly used in circuits in whichcircuits in whichthere is a load resistance in series with the detector. The outpthere is a load resistance in series with the detector. The output is read as aut is read as a

change in the voltage drop across the resistorchange in the voltage drop across the resistor..

Light Detection : Detector characteristicsLight Detection : Detector characteristics

Responsivity - Defined as the detector output per unit of input power.

The units of responsivity are either amperes/watt

(alternatively milliamperes/milliwatt or

microamperes/microwatt.

Quantum efficiency Defined as the effectiveness of the incident

radiant energy for producing electrical current in a

circuit. It may be related to the responsivity by the

equation:

Q = 100 x Rd x hv = 100 xRd (1.2395/ ).

Noise equivalent power (NEP) - Defined as the radiant power that

produces a signal voltage (current) equal to the noise

voltage (current) of the detector.

NEP=IAVN/VS(f)1/2

where I is the irradiance incident on the detector of

areaA, VN is the root mean square noise voltage

within the measurement bandwidth f, and VS is the

root mean square signal voltage.

Light DetectionLight Detection

MaterialsMaterials

Silicon (Si)Silicon (Si) Least expensiveLeast expensive

Germanium (Germanium (GeGe)) ClassicClassic detectordetector

Indium galliumIndium gallium

arsenide (InGaAs)arsenide (InGaAs) Highest speedHighest speed

Responsivity(A/W)

Wavelength nm500 1000 1500

Silicon

Germanium

InGaAs

QuantumEfficiency = 1

0.1

0.5

1.0


7/19

Optical Fiber

Professor Charles Kao who has been recognized as theinventor of fiber optics is receiving an IEE prize from

Professor John Midwinter(1998 at IEE Savoy Place, London, UK; courtesy of IEE)

Optical FiberAn optical fiber is a flexible filament of very clearglass and is capable of carrying information in theform of light. This filament of glass is a littlethicker than a human hair.

Dielectric Waveguides and Optical Fibers

Step Index Fiber

Optical fiber structure

The difference in refractive index between the core and cladding is < 0.5%.

The refractive index of the core is higher than that of the cladding, so that

light in the core strikes the interface with the cladding at a bouncing angle

and is trapped in the core by total internal reflection.

The cladding is the layer

completely surroundingthe core.

The core, or the axial part ofthe optical fiber, is the lighttransmission area of the fiber.

A mode is a defined path in which light travels.

A light signal can propagate through the core of the optical fiber on a

single path (single-mode fiber) or on many paths (multimode fiber). The

mode in which light travels depends on geometry, the index profile of

the fiber, and the wavelength of the light.

Single-mode fiber has the advantage of high information-carrying

capacity, low attenuation and low fiber cost, but multimode fiber hasthe advantage of low connection and electronics cost that may lead to

lower system cost.

Dielectric Waveguides and Optical Fibers

Multimode vs. Single-mode

Step Index Fiber

Schematic diagram of Step Index Fiber

n

y

n2 n1

Cladding

Core z

y

r

Fiber axis

Normalized

index difference

1

21

n

nn =

Typically


8/19

n1

n2

21

3

nO

n1

21

3

n

n2

OO' O''

n2

Multimode Step Index Fiber

Ray paths are different so thatrays arrive at different times.

Graded Index Fiber

Ray paths are different butso are the velocities alongthe paths so that all the raysarrive at the same time.

23

The Graded Index (GRIN) Optical Fiber

n decreases step by step from one

layer to next upper layer; very thin

layers.

n decrease in continuous gives a ray

path changing continuously.

TIR

A ray in thinly stratified medium

becomes refracted as it passes from one

layer to the next upper layer with lowern

and eventually its angle satisfies TIR.

In a medium where n decreases

continuously the path of the ray

bends continuously.

The Graded Index (GRIN) Optical Fiber

TIR

Light Absorption and Scattering

Attenuation

The reduction in signal strength is measured as attenuation.

Attenuation measurements are made in decibels (dB). The decibel is a

logarithmic unit that indicates the ratio of output power to input

power.

Each optical fiber has a characteristic attenuation that is normally

measured in decibels per kilometer (dB/km).

Optical fibers are distinctive in that they allow high-speed

transmission with low attenuation.

k

z

E Medium

Attenuation = Absorption Scattering+ Extrinsic factor+

Light Absorption and Scattering

Absorption

Lattice absorption through a crystal

z

A solid with ions

Light direction

k

Ex

The field in the wave oscillates the ions which consequently generate

"mechanical waves in the crystal; energy is thereby transferred from

the wave to lattice vibrations.


9/19

Scattered waves

Incident waveThrough wave

A dielectric particle smaller than wavelength

Rayleigh scattering involves the polarization of a small dielectric

particle or a region that is much smaller than the light wavelength.

The field forces dipole oscillations in the particle (by polarizing it)

which leads to the emission of EM waves in "many" directions so thata portion of the light energy is directed away from the incident beam.

Rayleigh scattering

Displacing electron with

respect to positive nuclei.

Oscillating charge = Alternating current

Radiates EM waves

Light Absorption and Scattering Attenuation in Optical Fibers

Optical Fiber Attenuation vs. wavelength

Fiber LossFiber Loss

Attenuation in Optical Fibers

Attenuation vs. wavelength

Stretching of Si-O bondsin ionic polarization

induced by EM wave,which is around 9 m.

Stretching of Si-O bondsin ionic polarization

induced by EM wave,which is around 9 m. Presence of hydroxyl ions (water) as

an impurity.Stretching vibration of OH- bonds at2.7 m. Its overtones at 1.0 & 1.4 m.

combinationof Si-O & 1.4 m

Micro-bending loss

Attenuation in Optical Fibers

Sharp bends change the local waveguide geometry that can lead to waves escaping.

The zigzagging ray suddenly finds itself with an incident angle that gives rise to either atransmitted wave, or to greater cladding penetration; the field reaches the outside medium andsome light energy is lost.

Escaping wave

c

Microbending

R

Cladding

Core

Field distribution

Small changes in the refractive index of the fiber due to induced strains when it is bent duringits use, e.g., when it is cabled and laid.

Induced strains change n1and n

2, and hence affect the mode field diameter, that is field

penetration into the cladding.

Macrobending loss crosses over into microbending loss when the radius of curvaturebecomes less than a few centimeters.


10/19

Fiber Fabrication

Fiber Materials Glasses and Plastics It must be possible to make long, thin flexible fibers from the materials.

The material must be transparent at a particular optical wavelength in orderfor the fiber to guide light efficiently.

Physically compatible materials that have slightly different refractiveindices for the core and cladding must be available

Silica Glass Fibers Glass do not have well defined melting point. The glass become to soften at high

temperature (>1000C), it became viscous liquid. SiO2:GeO2 core; SiO2 cladding

SiO2:P2O5 core; SiO2 cladding

SiO2 core; SiO2:B2O3 cladding

SiO2:GeO2/B2O3 core; SiO2:B2O3 cladding

Dopant addition (mol %)

Refractiveindex

1.46

1.48

1.445 10 15 20

GeO2

P2O5

B2O3

SiO2 @ 850 nm

Fiber materials

Halide Glass Fibers

Active Glass Fibers

Chalgenide Glass Fibers

Plastic Optical Fibers: POF

Short distance (100 m), very flexible, relaxation of connector tolerance, low cost

polymethylmethacrylate (PMMA) or perifluorinated polymer (PFP)

High non-linearity optical properties for all optical switch or fiber lasers

Chalcogen elements are doped: S, Se, Te

Amplification, Attenuation, Phase retardation

Rare earth elements are doped (0.005-0.05 mole%): atomic no. 57-71, Er, Pr

Extremely low transmission losses at mid-IR (@0.28 m) 0.010.001 dB/km)

ZrF4, BaF2, LaF3, AlF3, NaF

Fabricating long lengths of fibers is difficult.

Outside Vapor-Phase Oxidization

Vapor-Phase Axial Deposition

Modified Chemical Vapor Deposition

Plasma-Activated Chemical Vapor Deposition

Double-Crucible Method

Fiber Fabrication

Fiber Fabrication

Schematic illustration of a fiber drawing tower.

Fiber Drawing

Preform feed

Furnace 2000C

Thicknessmonitoring gauge

Take-up drum

Polymer coater

Ultraviolet light or furnacefor curing

Capstan

Preform


11/19

Vapors: SiCl4+ GeCl4+ O2

Rotate mandrel

(a)

Deposited sootBurner

Fuel: H2

Target rod

Deposited Ge doped SiO2

(b)

Furnace

Porous sootpreform with hole

Clear solidglass preform

Drying gases

(c)

Furnace

Drawn fiber

Preform

Reaction of gases in the burnerflame produces glass soot that

deposits on to the outside surface

of the mandrel.

The mandrel is removed and the hollowporous soot preform is consolidated;

the soot particles are sintered, fused,

together to form a clear glass rod.

The consolidatedglass rod is used as

a preform in fiber

drawing.

Outside Vapor Deposition (OVD)

Schematic illustration of OVD and the preform preparation for fiber drawing

SiCl4(gas) + O2 (gas) SiO2 (solid) + 2Cl2 (gas)GeCl4(gas) + O2 (gas) GeO2 (solid) + 2Cl2 (gas)

Outside Vapor Deposition (OVD)

The soot rod fed into the

consolidation furnace for sintering.

Glass preform fed into the fiber

drawing furnace

Optical CablesOptical Cables

Single mode and MultimodeSingle mode and Multimode

Single fiber and Fiber arraysSingle fiber and Fiber arrays

Polished facePolished face

Strain reliefStrain relief

Parameters: Insertion Loss, Attenuation,Parameters: Insertion Loss, Attenuation,

min bend radius, Face anglemin bend radius, Face angle

ExpensiveExpensive

Single FiberSingle Fiber

SC - MultimodeST - MultimodeDuplex LC

FC Single mode MU Single Mode E2000 Multimode


12/19

Fiber ArraysFiber Arrays

MTP test from Mipox

Multilayer ArraysMultilayer Arrays

XMP from Xanoptix

Polymer Optical WaveguidesPolymer Optical Waveguides

Requirements:Requirements:

Compatible with standard PWB TechnologiesCompatible with standard PWB Technologies

High performance (low optical loss)High performance (low optical loss)

Robust (>230 degrees C, >10 sec.)Robust (>230 degrees C, >10 sec.)

Dense (


13/19

Processing StepsProcessing Steps

Polymer Optical WaveguidesPolymer Optical Waveguides Polymer Optical WaveguidesPolymer Optical WaveguidesSamples

http://matlib.kjst.ac.kr/~optoelec/research/waveguide/p-waveguide.html


14/19

Optical Backplanes Speed DataOptical Backplanes Speed Data

In DaimlerChrysler's optical

backplane, the beam from

a laser diode passes

through one set of lenses

and reflects off a

micromirror before

reaching a polymer

waveguide, then does the

converse before arriving at

a photodiode and changing

back into an electrical

signal. A prototype

operates at 1 Gb/s.

FreeFree--Space Interconnects Pack inSpace Interconnects Pack in

Data ChannelsData Channels

An experimental module from theUniversity of California, SanDiego, just 2 cm high, connectsstacks of CMOS chips. Eachstack is topped with an opticschip [below center] consisting of256 lasers (VCSELs) andphotodiodes. Light from the

VCSELs makes a vertical exitfrom one stack [below, left] and avertical entry into the other. Inbetween it is redirected via adiffraction grating, lenses, analignment mirror [center], andanother grating. Each of thedevice's 256 channels operatesat 1 Gb/s.

Optical SensingOptical SensingTypical sensing system configuration using photons

Light source

Optical detector

Optional optical

detector

Ambient (light):

noise source

Ambient (light):

noise source

Electronics

Subject of

interest

signal+noise

Operating medium

Photon Sensing System IssuesPhoton Sensing System Issues

Selection of Light Sources

Selection Light Detectors

Minimizing effect of background noise

resulting from ambient light sources

System Performance Resolution

Speed

Accuracy


15/19

Fiber Optics For Measurement ApplicationsFiber Optics For Measurement ApplicationsTemperature Measurement Example:Technology - Light absorption/transmission properties of gallium

arsenide (GaAs)

Fiber

Semiconductor

Crystal

Dielectric

Mirror

Teflon

Technology - Fluoresence-decay of phosphor.

Temp. abs

abs = f(T)

Fiber Optic Temperature Probe

FiberMirror

Jacket

Timedecay = f(temp.)

Fiber Optic Temperature Probe

Phosphor

Light

Light

Fiber Optics For Measurement ApplicationsFiber Optics For Measurement ApplicationsFiber Optic Chemical Sensors (FOCS):

FiberDielectric

Mirror

TeflonChemical

Cladding removed substituted by suitable

chemical

Light

Escape light

Amount of light loss is proportional to the amount of chemical present

FBG (Fiber Bragg Grating)FBG (Fiber Bragg Grating) _FBG (Fiber Bragg Grating)FBG (Fiber Bragg Grating)

I

II

= Grating Period


16/19

Operation Principle of FBG SensorOperation Principle of FBG Sensor

n+

1,

2, ...,

n, ...,

x

n+

n

1,

2, ...,

n, ...,

x

1,

2, ......,

x

n

When the fiber optic sensor is initially mounted to a

structure, it's in resonance with laser wavelength ln.

Mounting block that

attaches fiber optic

sensor to the structure

Structure starts to pull mounting blocks apart ,

which stretches the fiber optic sensor. The

resonance of fiber optic sensor is now shifted.

Reflection

Without StrainReflection

Without Strain

FBG SensingFBG Sensing

FBG Sensor Temperature Response

30 40 50 60 701550.7

1550.8

1550.9

1551

1551.1

1551.2

1551.3

Temperature,oC

Wavele

ngth,nm

Athermal, max shift: 21.6 pm (2.7 GHz) from 24oc to 70

oC

Conventional, 10.4 pm/oC (1.3 GHz/

oC)

Standard FBG Sensor

Temperature Response

Athermal FBG Sensor

Temperature Response

Utilization of FBG Characteristics for measurementUtilization of FBG Characteristics for measurement

Accelerometer

Accelerometer


17/19

Other FBG SensorsOther FBG Sensors FBG For Structure Health MonitoringFBG For Structure Health Monitoring

FBG Railway SensingFBG Railway Sensing

Wavelength(nm)

Time (0.01 sec)

Typical Structure Health MonitoringTypical Structure Health Monitoring

SystemSystemBroadband coupler 1 2 3BroadbandSource

12 3

Tunable Filter

Optical Subsystem

Reflected

Light

23 3

FBGs

321

Detection

Broadband coupler 1 2 3Tunable

Source

12 3

Tunable Filter

Optical Subsystem

Reflected

Light

23 3

FBGs

321

Detection


18/19

Broadband coupler

SLED or Laser

1

2

3Low Contrast

Fabry-Perot

Filter

12 3

Wavelength

Locker

Light Source

Trigger Module

Timing

Generator

Interrogation Unit (High

Speed Signal Conditioning,

Sampling and ADC)

Microcontroller

Ethernet

Interface

PC

Optical Subsystem

Electrical Subsystem

Pulsed

Broadband

light

Reflected

Light

FBG-LTDM Structure Monitoring System

23 3

FBGs

ExternalInternal

321 12 3

FBG-LTDM Structure Monitoring System Timing Example

Time (ns)

1

2

3

1 2 3

FBGs

12 3 23 3

10 meters 10 meters 10 meters

Light Pulse

1st. Reflected Wavelength

2nd. Reflected Wavelength

3rd. Reflected Wavelength

50 100 150 200 250 150 200

Tp

Tfr

Tsw

Tsl

Light Pulse

12 3 12 3

Light Pulse

ConclusionsConclusions

Interconnect problem significant in ultra highInterconnect problem significant in ultra high

speed data communicationspeed data communication

Performance of Electrical lnterconnects will limitPerformance of Electrical lnterconnects will limit

high performance system throughputhigh performance system throughput

OIs will provide significant performance boostOIs will provide significant performance boost

but not completely replacebut not completely replace EIsEIs

Optical Sensing will be deployed in new areasOptical Sensing will be deployed in new areas

that were not feasible with electrical sensorsthat were not feasible with electrical sensors

WWavelengthavelength DDivisionivision MMultiplexingultiplexingWDM enables transmission of multiple communication channels

through a single fiber using various colors of light

Detector

MUX =Multiplexer

DEMUX =Demultiplexer

EDFA =Erbium Doped Amplifier

n

1

n

1

2

1

2

1

Coarse WDM (CWDM): Transmission of a few widely spaced channels

Dense WDM (DWDM): Transmission of many closely spaced channels

MUX DEMUXEDFA Optical Fiber (Singlefiber, multiplewavelengths)

Add/DropChannel

TunableLaser

Source orDFBLaser

Tunable Filter


19/19

ReferencesReferences International Technology Roadmap for Semiconductors (ITRS), 2001

R. Havemann and J.A Hutchby, High-Performance Interconnects: Anintegration Overview, Proc. Of IEEE, Vol.89, May 2001

D.A.B Miller, Physical reasons for optical interconnections, Int. Journal ofOptoelectronics 11, 1997, pp.155-168.

MEL-ARI: Optoelectronic interconnects for Integrated Circuits Achievements 1996-2000

Linking with light - IEEE Spectrum

http://www.spectrum.ieee.org/WEBONLY/publicfeature/aug02/opti.html

Optically Interconnected Computing Group

http://www.phy.hw.ac.uk/~phykjs/OIC/index.html

Optoelectronics -VLSI system integration Technological challenges

www.phy.hw.ac.uk/~phykjs/OIC/Projects/SPOEC/MSEB2000/MSEB2000.pdf

Date post:	06-Apr-2018
Category:	Documents
Upload:	shiela-maury
View:	232 times
Download:	0 times

Optical Interconnect

Documents