Ultrafast photonics : proceedings of the Fifty-Sixth Scottish Universities Summer School in Physics, St. Andrews, September 2002

356 Pages·2011·12.96 MB·English

by  A Miller

ULTRAFAST PHOTONICS
Proceedingsof theFifty-Sixth
ScottishUniversities SummerSchoolinPhysics
StAndrews, September 2002
ANATOAdvancedStudyInstitute
Editedby
AMiller—Universityof StAndrews
DTReid—Heriot-WattUniversity
D MFinlayson —Universityof StAndrews
SeriesEditor
POsborne—UniversityofEdinburgh
Co-publishedby
ScottishUniversities SummerSchoolinPhysics &
InstituteofPhysics Publishing,BristolandPhiladelphia
© IOP Publishing Ltd 2004
Copyright©2004
TheScottishUniversitiesSummerSchoolinPhysics
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byphotostat,microfilmoranyothermeanswithout
writtenpermissionfromthepublishers.
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Co-publishedby
SUSSPPublications
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TheKing’sBuildings,MayfieldRoad,EdinburghEH93JZ,Scotland.
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PrintedintheUKbyMPGBooksLtd,Bodmin,Cornwall.
© IOP Publishing Ltd 2004
SUSSP Proceedings
1 1960 DispersionRelations
2 1961 Fluctuation,RelaxationandResonanceinMagneticSystems
3 1962 PolaronsandExcitons
4 1963 StrongInteractionsandHighEnergyPhysics
5 1964 NuclearStructureandElectromagneticInteractions
6 1965 PhononsinPerfectandImperfectLattices
7 1966 ParticleInteractionsatHighEnergy
8 1967 MethodsinSolidStateandSuperfluidTheory
9 1968 PhysicsofHotPlasmas
10 1969 QuantumOptics
11 1970 HadronicInteractionsofPhotonsandElectrons
12 1971 AtomsandMoleculesinAstrophysics
13 1972 PropertiesofAmorphousSemiconductors
14 1973 PhenomenologyofParticlesatHighEnergy
15 1974 TheHeliumLiquids
16 1975 Non-linearOptics
17 1976 FundamentalsofQuarkModels
18 1977 NuclearStructurePhysics
19 1978 MetalNon-metalTransitionsinDisorderedSolids
20 1979 Laser-PlasmaInteractions:1
21 1980 GaugeTheoriesandExperimentsatHighEnergy
22 1981 MagnetisminSolids
23 1982 Laser-PlasmaInteractions:2
24 1982 Lasers:Physics,SystemsandTechniques
25 1983 QuantitativeElectronMicroscopy
26 1983 StatisticalandParticlePhysics
27 1984 FundamentalForces
28 1985 SuperstringsandSupergravity
29 1985 Laser-PlasmaInteractions:3
30 1985 SynchrotronRadiation
31 1986 LocalisationandInteraction
32 1987 ComputationalPhysics
33 1987 AstrophysicalPlasmaSpectroscopy
34 1988 OpticalComputing
35 1988 Laser-PlasmaInteractions:4
36 1989 PhysicsoftheEarlyUniverse
/continued
© IOP Publishing Ltd 2004
SUSSP Proceedings
(continued)
37 1990 PatternRecognitionandImageProcessing
38 1991 PhysicsofNanostructures
39 1991 HighTemperatureSuperconductivity
40 1992 QuantitativeMicrobeamAnalysis
41 1992 SpatialComplexityinOpticalSystems
42 1993 HighEnergyPhenomenology
43 1994 DeterminationofGeophysicalParametersfromSpace
44 1994 SimpleQuantumSystems
45 1994 Laser-PlasmaInteractions5:InertialConfinementFusion
46 1995 GeneralRelativity
47 1995 LaserSourcesandApplications
48 1996 GenerationandApplicationofHighPowerMicrowaves
49 1997 PhysicalProcessesintheCoastalZone
50 1998 SemiconductorQuantumOpto-electronics
51 1998 MuonScience
52 1998 AdvancesinLasersandApplications
53 1999 SoftandFragileMatter
54 2000 TheRestlessUniverse
55 2001 HeavyFlavourPhysics
56 2002 Ultrafastphotonics
57 2003 LargeHadronColliderPhenomenology
58 2004 HadronPhysics
59 2004 SoftCondensedMatterinMolecularandCellBiology

© IOP Publishing Ltd 2004
Lecturers
DonalBradley ImperialCollegeofScienceTechnologyandMedicine
TakisHadjifotiou NortelNetworks
JornHvam TechnicalUniversityofDenmark
JaroslavKovac SlovakUniversityofTechnology
ThomasFKrauss UniversityofStAndrews
AlanMiller UniversityofStAndrews
DavidABMiller StanfordUniversity
Jean-LouisOudar CNRSLaboratoirePhotoniqueetNanostructure
RichardVPenty UniversityofCambridge
DerryckTReid Heriot-WattUniversity
PeeterSaari UniversityofTartu
SolomonMSaltiel SofiaUniversity
IforDWSamuel UniversityofStAndrews
WilsonSibbett UniversityofStAndrews
GeorgeStegeman UniversityofCentralFlorida
OsamuWada KobeUniversity
AlekseiMZheltikov MVLomonosovMoscowStateUniversity

vii
© IOP Publishing Ltd 2004
Executive Committee
ProfAlanMiller UniversityofStAndrews DirectorandCo-Editor
DrTomBrown UniversityofStAndrews Secretary
DrDerryckReid Heriot-WattUniversity TreasurerandCo-Editor
DrDavidFinlayson UniversityofStAndrews Co-Editor
International Advisory Committee
ProfDavidABMiller StanfordUniversity,USA
ProfGeorgeStegeman UniversityofCentralFlorida,USA
ProfAlekseiMZheltikov MVLomonosovMoscowStateUniversity,Russia

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© IOP Publishing Ltd 2004
Preface
This book is the Proceedings of the 56th Scottish Universities Summer School in Physics
(SUSSP56),on‘UltrafastPhotonics’heldattheUniversityofStAndrews,Scotlandbetween
1stand14thSeptember2002.
Ultrafastphotonicshasbecomeaninterdisciplinarytopicofhighinternationalresearch
interestbecauseofthespectaculardevelopmentofcompactandefficientlasersproducingop-
ticalpulseswithdurationsinthefemtosecondtimedomain.ThescopeoftheSchoolranged
fromtherelevantfundamentalphysicsofopticalinteractionsandmaterialpropertiesthrough
to new system concepts for ultrahigh-capacity data transfer/processing using femtosecond
pulses.Areasofscientificbreakthroughandsubsequenttechnologicaladvancewereempha-
sised.TheSchoolincludedresearchersfrommajorcollaborativeresearchinitiativesinultra-
fastphotonicsinEurope,USAandJapan.
‘Photonics’encompassesoptics-baseddevices,componentsandsystemsforinformation
technology.Photonicshasbeenthefoundationuponwhichthemajoradvancesincommu-
nicationshavebeenmade.Presentdaylong-haultelecommunicationsystemsarealmosten-
tirely based on the transmission of short bursts or pulses of laser light along silica optical
fibreswithErbium-dopedfibreamplifiersinsertedtoregeneratethesignalsperiodically.Op-
ticalfibreshavetheadvantageoflowloss,highreliability,hugeinformationcarryingcapac-
ityand,mostimportant,cost.Thephenomenalsuccessofopticalfibrecommunicationshas
created a substantial opto-electronics industry that provides efficient laser sources, high-
speedmodulators,opticalamplifiersanddetectors.
Althoughopticaldatatransmissionisnowwellestablished,thefullpotentialhasnotbeen
reachedtomeettheever-increasingdemandsofdata-communication.Indeed,photonics-re-
lated component and system developments are still relatively immature in terms of data
switching, routing and component integration. Current system approaches will eventually
cease to meet the ever increasing demand of information transfer. Novel approaches and
ideasareneeded;theserequirearethinkofthefundamentalissuesoflightgeneration,new
optoelectronic materials, laser-semiconductor interactions, ultrashort pulse propagation,
nanometricstructures,deviceminiaturisationandintegration.Theexplosionoftheinternet
willdemandthatexistingwavelengthdivisionmultiplexing(WDM)schemeswillneedtobe

complementedwithtime-domainmultiplexing(TDM)techniquesinvolvingdigitaloptical
signals using ultrashort laser pulses. Ultimately, photonics involving ultrashort pulses of
femtoseconddurationoffersexcitingopportunitiesatmulti-Tb/sdatarateswiththegoalof
complete optical-electronic systems combined on a single chip. SUSSP56 was timely in
bringingworldexpertsinthisfieldtogetherwithyoungpeoplewhoareexcitedbythisvery
activeareaofresearch.
SUSSP56washeldintheSchoolofPhysicsandAstronomyandJohnBurnetHallonthe
NorthHaughoftheUniversityofStAndrewsandclosetotheancienttown’sshops,pubs,
beachesandhistoricalmonumentsandadjacenttothefamous‘OldCourse’,theveryfirstgolf
course. The School was supported as a NATOAdvanced Study Institute and a European
Community Summer School.The 116 participants from 20 countries attended 44 lectures
presentedby17lecturersover11workingdays.Anumberofdiscus-sionsessionscreated
ix
© IOP Publishing Ltd 2004
stimulatingdebateonthekeyissuesandstudentspresentedtheirownworkin67posterpa-
persintwoverylivelysessions.TheSchoolwasfurtherenrichedbythevisitofagroupof
6 Japanese scientists who gave overviews of research activities in ultrafast photonics at
FESTA,AISTandTohokuUniversity.
Abusysocialprogrammekepteverybodywelloccupiedoutsideoftheformalsessions.
ParticipantssampledtheScottishscenerywithaclimbupBenVrackie,tripstoStirlingCas-
tle,theWallace(ofBraveheartfame)Monument,andatourofStAndrews.Theuniversity
gaveareceptionandaformaldinnerprovidedatasteofhaggis.‘Pubcrawls’ofthenumer-
ous StAndrews establishments were organised by the local post-graduate students when
many were introduced to the effects (good and not so good) of malt whisky.An ‘Interna-
tional Evening’allowed students to sample food and drinks from the many nations repre-
sented. Some participants braved a swim in the North Sea from the adjacentWest Sands
Beachwhileothersattemptedgolf,puttingorjustwalkingthelinks.Ahighlightformanywas
thefinalnightceilidhincludingtraditionalScottishdancing.Itisourhopethatthefriendships
thatformedduringtheSchoolwillleadtolife-longbondsandlinkswithfruitfulresearchcol-
laborationsspanningmanyinternationalbordersandcultures.
Theorganisersaregratefulforthehelpofmanyorganisationsandindividualsinthesuc-
cessoftheschool.Wewouldliketothankoursponsors;NATOandtheEuropeanCommu-
nity, the Engineering and Physical Sciences Research Council, the National Science
Foundation(USA),ScottishEnterprise,theScottishBranchofLEOS,InstituteofPhysics
Publishing,andSUSSP.TheDirectorandallparticipantsgreatlyappreciatedthetimeandef-
fortputinbythelocalorganisingteamledbyTomBrownasSchoolSecretaryandDerryck
ReidasTreasurer.DavidFinlaysondeservesspecialthanksforprovidinghisexpertguidance
fromover40yearsofexperiencewithSUSSPSchools,presentinghisspecialistknowledge
ofmaltwhiskies,andcontributingmanyhoursofdiligentconvertingandeditingthechap-
tersofthisbook.
The staff of John Burnet Hall, headed by Jackie Mathews, again provided a very high
qualityandfriendlyresidentialservice.Thanksarealsoduetothestaffandstudentsofthe
SchoolofPhysicsandAstronomyforprovidingwillingassistanceinmanytasksthatcon-
tributedtotheoverallsuccessoftheSchool.
AlanMiller
StAndrews,September2003
Editors’Note
Thechapters,writtenbyinternationallyrenownedexpertsinthefieldofultrafastphotonics,
arebasedonthelecturespresentedattheschool.Theyprovidetutorial-styleintroductionsto
thevarioustopics,suitableforpost-graduateresearchstudentsandotherswithabasicknowl-
edgeofphotonics.Thebookprogressesfromidentifyingsomeofthesystemsissuesthrough
fundamental optical physics to future devices and applications.The editors would like to
thanktheauthorsfortheirexcellentandtimelycontributionstothisvolume.MichaelMazilu
isacknowledgedforhisexperthelpinhandlingthemanydifferentsubmittedfiletypesand
convertingthemintotheLaTexformatofthefinalversion.
x
© IOP Publishing Ltd 2004
Contents
Prospectsforultrafastdigitalprocessing.........................................................................1
DavidABMiller
Femtosecondsourcesbasedonvibroniccrystals...........................................................21
TomBrownandWilsonSibbett
Shortpulsegenerationusingsemiconductorlasers.......................................................43
RichardPenty
Measuringultrafastlaserpulses.....................................................................................59
DerryckTReid
Cascadednonlinearopticalprocesses.............................................................................73
SolomonMSaltiel
Spatialbeaminstabilitiesduetoinstantaneousnonlinearmechanisms....................103
GeorgeIStegeman
Planarphotoniccrystalmicrocircuitelements............................................................123
ThomasFKrauss
Propagationofshortlightpulsesinphotonicband-gapstru.....................................141
AlekseiMZheltikov
Ultrafastspectroscopystudiesofsemiconductors.......................................................193
JaroslavKovac
Ultrafastsemiconductorall-opticalprocessingdevicesfortelecommunicationsappli-
cations..............................................................................................................................225
Jean-LouisOudar
Ultrafastprocessesinsemiconductoropticalamplifiersandmodulators.................265
ø
J rnMHvam
Towardspolymerlasersandamplifiers........................................................................291
IforDWSamuel
Opticalspintronicsforswitching..................................................................................305
AlanMiller
Localisedwavesinfemtosecondoptics.........................................................................317
PeeterSaari
PosterSessions................................................................................................................341
ListofParticipants.........................................................................................................345
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© IOP Publishing Ltd 2004
1
Ultrafast digital processing
DavidABMiller
StanfordUniversity,USA
1 Introduction
Thischapterwilldealwithsomepossibleapplicationsofultrafastphotonictechnology.We
willdiscusssomeofthekeyfeaturesofultrafastphotonicsthatmightbeusefulindigitalin-
formation processing, and go on to discuss some specific applications currently being re-
searched, including optically assisted analog-to-digital conversion, ultrafast optical gates,
opticalclockdistribution,andopticalinterconnects.Ineachcasewewillgivesomeofthe
backgroundmotivationfortheapplication,aswellasgivingaspecificresearchexample.
Itisworthpointingoutattheoutsetthatmakingthematchbetweentheexcitingoppor-
tunitiesofanewtechnology,suchasultrafastphotonics,andpracticalusesthatwilldisplace
existingtechnologyinrealapplicationsisachallengingtask.Thepracticalworldisnore-
specter of how erudite or beautiful is the physics with which we are working, or, for that
matter,howsmartwethinkweare!Theapparentlymostminorofpracticaldetailscanpre-
ventanewtechnologyfromactuallybeingused.Existingtechnologiescanbeverydifficult
todisplacebecauseexistingsystemsareoftenoptimizedroundthestrengthsandlimitations
of that technology, because the investments have often been made that make that existing
technology inexpensive, and because engineers and technicians are already trained to de-
sign,installandmaintainthem.
Onthepositiveside,weshouldnotethatnewtechnologiescertainlydodisplaceexisting
ones,andalsofindapplicationstheexistingtechnologiescouldnotsupport.Insodoing,it
isoftensurprisingwhataspectsofanewtechnologyarethekeytoitssuccessfuluse.Therea-
sonforthedominanceofsiliconelectronicsovergermaniumorgalliumarsenideistheprop-
ertiesofthesilicon,silicon-oxideinterface,withitsverylowdensityofsurfacestates,which
allowsverylargenumbersoftransistorstobemadereliably.Theimportantparameterforap-
plicationswasnot,asscientistshaveoftenimagined,theperformanceoftheindividualtran-
sistor,butratherthematerialpropertiesthatenableustomakelargenumbers.Itisalsooften
surprisingthatthefinaldominantapplicationsofarevolutionarytechnologyhavelittletodo
withtheapplicationsimaginedbytheoriginalscientistsorbusinesspeople.(Forexample,
ThomasWatson,thenchairmanofIBM,saidin1943thathethoughttherewasaworldmar-
ketformaybefivecomputers,andKenOlson,president,chairman,andfounderofDigital
© IOP Publishing Ltd 2004