Future prospects of the op-cal levita-on experiment · 2017-04-28 · Future prospects of the op-cal levita-on experiment ( ) KAGRA observatory, Ins-tute for cosmic ray research,

Futureprospectsoftheop-callevita-onexperiment( )

KAGRAobservatory,Ins-tuteforcosmicrayresearch,

UniversityofTokyo

NAGANOKoji( )

AndoLabChukanseminar(TheUniversityofTokyo,Hongo,Apr.27,2017)


Q.WhoamI?A.I’mNAGANOKoji,1styearofPh.D.course,belongingtoKAGRAobservatory,ICRR,UniversityofTokyo.

Q.WhatdidIdoinmymastercourse?A.Istudiedonthequantumnoisereduc-ontechniqueforKAGRA(ponderomo-vesqueezingandhomodynedetec-on)inKashiwa,calledQND(quantumnon-demoli-on)exp..Fordetail,pleaseseemymasterthesisonJGW-P1706052.Inaddi-on,IvisitedCaltechandU.Grasgow.WhatIdidinCaltechwillbepublishedaspapersomeday.

Q.WillItalkaboutwhatIdidinmastercourse?A.No,Iwillnot.Iwilltalkaboutmyfuturework,“op-callevita-onexperiment,”whichIwilldoinmyPh.D.course.

Overture


•  Introduc-on•  Schedule•  Applica-onsofop-callevita-ons•  Experimentalsetupdesignproposal•  Problems•  Conclusion•  Summary

Outline


•  Forgravita-onal-wave(GW)detec-onsorstudiesofthemacroscopicquantummechanics,extremelylownoisesystemsarerequired.

•  Abouttheseismicnoisereduc-on,suspensionsystemsareo`enused.

•  However,thesuspensionsystemsinduceaddi-onalthermalnoises.

Introduc-on

K.Komori,Masterthesis,UniversityofTokyo(2016)

5-mgmirrorsuspension

E.Hirose+,CQG(2014)SuspensionsystemofKAGRA(Cryogenicpart)


•  Suspensionthermalnoiseisoneofthemajornoisesourcesofinterferometerswhichclosethesensi-vitywindowreachingthestandardquantumlimit(SQL).

•  ReachingSQLisakindofmilestoneofthetestofthemacroscopicquantummechanics.

•  Inaddi-on,ifwecandemonstratetobeatSQL,thatis,toreducethequantumnoise,itleadstoimprovementofthesensi2vityofGWdetectors.

Introduc-on


•  Thesuspensionthermalnoisecanbeex-nguishedwhenmassesarelevitatedwithop-calradia-onpressureinsteadofsuspendedwithmechanicalwires.

•  Thistechniqueiscalledasanop-callevita-on(OL).

Introduc-on

fluctua-on

gravity

gravity

radia-onpressure

tension


Introduc-on

光学浮上が熱い

2

mass scale

sensitivity(m/rtHz)

fg ng ug mg pg

-12

-11

-10

N. Kiesel+: PNAS 110, 14180 (2013) cavity / 0.15um / 10fg? / 64K, 4e-12 m/rtHz

-13

T. Li+: Science 328, 1673 (2010) T. Li+: Nature Physics 7, 527 (2011) tweezer / 1um / 1pg / 1.5mK, 1e-13 m/rtHz, Brownian velocity

A. Arvanitaki, A. A. Geraci : PRL 110, 071105 (2013) cavity / 0.2~75um / fg~pg / ~1e-14m/rtHz, GW

A. Ashkin+: Appl. Phys. Lett. 19, 283 (1971) tweezer / 20um / 10ng? / ?? m/rtHz

G. Guccione+: arXiv:1307.1175 cavity / 2mm / 0.3mg / ?? m/rtHz R. Kaltenbaek+ : Experimental Astronomy 34, 123 (2012)

cavity / 0.1um / 10fg? / ~1e-12m/rtHz?, MAQRO

S. Singh+: PRL 105, 213602 (2010) cavity+tweezer / 60um / 40ng / 1e-10m/rtHz

Y. Arita+: Nature Communications 4, 2374 (2013) tweezer / 4.4um / 0.1ng? / 40K, 1e-10 m/rtHz, gyroscope

Plankmass(22ug)

Y.Michimura,Seminarslide


Introduc-on

光学浮上が熱い

2

mass scale

sensitivity(m/rtHz)

fg ng ug mg pg

-12

-11

-10

N. Kiesel+: PNAS 110, 14180 (2013) cavity / 0.15um / 10fg? / 64K, 4e-12 m/rtHz

-13

T. Li+: Science 328, 1673 (2010) T. Li+: Nature Physics 7, 527 (2011) tweezer / 1um / 1pg / 1.5mK, 1e-13 m/rtHz, Brownian velocity

A. Arvanitaki, A. A. Geraci : PRL 110, 071105 (2013) cavity / 0.2~75um / fg~pg / ~1e-14m/rtHz, GW

A. Ashkin+: Appl. Phys. Lett. 19, 283 (1971) tweezer / 20um / 10ng? / ?? m/rtHz

G. Guccione+: arXiv:1307.1175 cavity / 2mm / 0.3mg / ?? m/rtHz R. Kaltenbaek+ : Experimental Astronomy 34, 123 (2012)

cavity / 0.1um / 10fg? / ~1e-12m/rtHz?, MAQRO

S. Singh+: PRL 105, 213602 (2010) cavity+tweezer / 60um / 40ng / 1e-10m/rtHz

Y. Arita+: Nature Communications 4, 2374 (2013) tweezer / 4.4um / 0.1ng? / 40K, 1e-10 m/rtHz, gyroscope

Plankmass(22ug)



•  Sofar,twotypes(ormore?)ofOLsformg-scalemirrorshavebeenproposed.

Introduc-on

tripodtypesandwichtype

Y.Kuwahara,Masterthesis,UniversityofTokyo(2016)

Y.Michimura+,arXiv(2017),Opt.Express(underreview)

G.Guccione+,PRL(2013)


Introduc-on

自由度と安定性

2016/01/27 修士論文審査会 22

自由度水平(x,y)並進鉛直(z)並進 x, y軸回転 z軸回転

復元力サンドイッチ構成の復元力光バネ重力なし

模式図

Ø  浮上鏡の曲率中心の運動（並進3自由度，回転3自由度）

dxdF

dβmg

z z z

Levitated mirror

dF

dβmg

dβ

mg

zz

z

o済済済

Y.Kuwahara,Masterthesisdefense,UniversityofTokyo(2016)


•  AdvantagesanddisadvantagesofthetwotypeOL:

Introduc-on

•  SincethesandwichtypeOLhasnotyetbeenexperimentallydemonstrated,wehavetodoit.–  Accordingtorumor,thetripodtypeOLhasbeendemonstratedalreadyinANU.

Y.Kuwahara,Masterthesis,UniversityofTokyo(2016)


Purposesoftheop2callevita2onexperiment•  Demonstra-ngtheop-callevita-onwithsandwichconfigura-on

•  Achievementofthesensi-vityreachingSQL.•  Testofthemacroscopicquantummechanics,thedevelopmentofthetechniquetoimprovethesensi-vityofGWdetectors,suchasKAGRA,andothersciences.

(andEduca-onofmyselfandjuniorstudents.)

Introduc-on


Atfirst,letmedivideourOLexperimentintofourphases.•  Phase-0(wearehere)–  Confirma-onofthepossibilityofthesandwichtypeOL.(theore-calstudyandR&D)

•  Phase-1–  Demonstra-onoftheOLwithsandwichconfigura-on.–  Nosensi-vityrequirement.

•  Phase-2–  Achievementofthesensi-vityreachingSQL.

•  Phase-3–  Testofthemacroscopicquantummechanicsandthedevelopmentofthetechniquetoimprovethesensi-vityofGWdetectors.

Schedule


4 6 8 10 12 2 4 6 8 10 12 2 4 8 12 3

Phase-0

Phase-1

Phase-2

Phase-3

ScheduleH29 (D1) H30 (D2) X (D3)

theore-calstudy

hor.stab.demo.

designsetupmechanics,op-cs,alignmentmethod

aux.cavitystudy

buildsetuplevitate1.6-mgmir.!

(3m)

(6m)(6m)

modifydesign

buynewmir.(1m)

designsetupchecknewmir.

check1.6-mgmir.

(6m)

reachSQL!!

writepaper

re-buildsetup(6m)

fiberMItest(8m) buildandtestLSS(6m)

(2m) writepaper

writepaperbuyitems

buildanothersetup(3m) enjoyscience!!!

writethesis

writepaper:deskwork

:labwork:exci-ngbutuncertainwork


4 6 8 10 12 2 4 6 8 10 12 2 4 8 12 3

Phase-0

Phase-1

Phase-2

Phase-3


theore-calstudy

hor.stab.demo.


aux.cavitystudy


(3m)

(6m)(6m)

modifydesign

buynewmir.(1m)


check1.6-mgmir.

(6m)

reachSQL!!

writepaper

re-buildsetup(6m)


(2m) writepaper

writepaperbuyitems


writethesis

writepaper


4 6 8 10 12 2 4 6 8 10 12 2 4 8 12 3

Phase-0

Phase-1

Phase-2

Phase-3


theore-calstudy

hor.stab.demo.


aux.cavitystudy


(3m)

(6m)(6m)

modifydesign

buynewmir.(1m)


check1.6-mgmir.

(6m)

reachSQL!!

writepaper

re-buildsetup(6m)


(2m) writepaper

writepaperbuyitems


writethesis

writepaper






Applica-onsofop-callevita-ons


4 6 8 10 12 2 4 6 8 10 12 2 4 8 12 3

Phase-0

Phase-1

Phase-2

Phase-3


theore-calstudy

hor.stab.demo.


aux.cavitystudy


(3m)

(6m)(6m)

modifydesign

buynewmir.(1m)


check1.6-mgmir.

(6m)

reachSQL!!

writepaper

re-buildsetup(6m)


(2m) writepaper

writepaperbuyitems


writethesis

writepaper:deskwork




光学浮上の応用先 • 古典力学と量子力学を繋ぐモデルの検証

R. Penrose: Gen. Rel. Grav. 28, 1572 (1996) A. Bassi+: Rev. Mod. Phys. 85, 471 (2013)

• 重力デコヒーレンスの観測 R. Kaltenbaek+: Experimental Astronomy 34, 123 (2012)

• 巨視的量子現象エンタングルメント、Schrödingerの猫 etc.

• 超高精度力センサ(～10-20 N/rtHz) 重力逆二乗則の検証、Casimir力 A. A. Geraci+: PRL 105, 101101 (2010) 重力波検出 A. Arvanitaki, A. A. Geraci: PRL 110, 071105 (2013)

• 量子情報的な応用(回転の自由度を利用)

4

• 










4

• 

Testofmacroscopicquantummechanics




提案されている検証方法

2016/01/27 修士論文審査会 9

Ø 巨視的な物体では，直接二重スリット実験をする代わりにそれに相当する実験をし，重ね合わせが生じるかどうか検証する。Ø  SQLへの到達が必要条件

LASER

PD PD

FI BS

com. mode diff. mode

com. mode

com. mode

diff. mode

diff. modedark portbright port

PRM Single photon

PD PD

FI

BS

source

Ground state mirror

|1⟩

|0⟩m or |1⟩m

|0⟩U or |1⟩U

|0⟩R or |1⟩R

Müller-Ebhardt+(2008) Marshall+(2003)

SQLに到達した振動子

同相モードと差動モードの重ねあわせ状態を観測

基底状態の振動子(SQL到達が必要)→ 単一光子で励起

単一光子源

振動子の orの重ねあわせ状態を観測

0m

1m










4

• 

Developmentofthenoisereduc-ontechniqueandGWdetec-on

gravityexperiment




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Displacemen

tsen

siWvity[m

/rtHz]�

K.Nagano,Masterthesisdefense,UniversityofTokyo(2017)






Schedule


4 6 8 10 12 2 4 6 8 10 12 2 4 8 12 3

Phase-0

Phase-1

Phase-2

Phase-3


theore-calstudy

hor.stab.demo.


aux.cavitystudy


(3m)

(6m)(6m)

modifydesign

buynewmir.(1m)


check1.6-mgmir.

(6m)

reachSQL!!

writepaper

re-buildsetup(6m)


(2m) writepaper

writepaperbuyitems


writethesis

writepaper:deskwork



Horizontalop-calspringdemonstra-on

ねじれ振り子の利用

2016/01/27 修士論文審査会 28

YAW

完全な自由質点のmg鏡の代わりにねじれ振り子を使用- やわらかい(共振周波数 ~10 mHz)- サンドイッチ構成の微小な復元力を感じうる

ü  ねじれ振り子の運動(YAW)の変化によってサンドイッチ構成の安定性を検証できる - もとの共振周波数からの上昇を観測

ü  g程度の鏡を使用できる - 0.5inch, 1inch, etc…

鏡の水平並進







Schedule


4 6 8 10 12 2 4 6 8 10 12 2 4 8 12 3

Phase-0

Phase-1

Phase-2

Phase-3


theore-calstudy

hor.stab.demo.


aux.cavitystudy


(3m)

(6m)(6m)

modifydesign

buynewmir.(1m)


check1.6-mgmir.

(6m)

reachSQL!!

writepaper

re-buildsetup(6m)


(2m) writepaper

writepaperbuyitems


writethesis

writepaper:deskwork



Experimentalconfigura-oninPhase-1-wavelength:1064nm-finesse:700(lower,upper)-inputpower:8.5W(lower)

2.6W(upper)-lev.mirrormass:1.6mg

-r=1.5mm,t=0.1mm-int.reflec-vity:0.9995(lev.)

0.992(l,u)-freq.noise:5x10-3Hz/rtHz

-suspensionreso.freq.:~1Hz-maincavityservoUGF:~20Hz(?)-op-calzenithangle<0.2deg-pressure:10-4Pa


Sensi-vityinPhase-1

102 103 104 105 106

Frequency [Hz]

10-20

10-19

10-18

10-17

10-16D

ispl

acem

ent n

oise

spe

ctru

m [m

/rtH

z] SQLquantum noisecoating thermalsubstrate thermalresidual gas thermalfrequency noiseseismic


•  Usethe1.6-mgmirror,whichwehavealready.•  Userela-velyhigh-finesse(~700)cavity.•  Userela-velysimplelaserstabiliza-onsystem(LSS).•  Lightisintroducedtothevacuumchamberthoughtop-calfibers.

•  Transmiredlightsinthemaincavi-esareextractedbypolarizingbeamsplirer(PBS)intheothercavi-estodecouplethecavi-es.

•  Tokeeptheop-calspringeffect,maincavi-esaresuspendedforvibra-onisola-ontodecreasetheunitygainfrequency(UGF)oftheirservo(~afew10Hz).

•  (Ifpossible)usenewdigitalcontrolsystem.

PointsinPhase-1


•  Usethe1.6-mgmirror,whichwehavealready.•  Userela-velyhigh-finesse(~700)cavity.•  Userela-velysimplelaserstabiliza-onsystem(LSS).•  Lightisintroducedtothevacuumchamberthoughtop-calfibers.

•  Transmiredlightsinthemaincavi-esareextractedbypolarizingbeamsplirer(PBS)intheothercavi-estodecouplethecavi-es.

•  Tokeeptheop-calspringeffect,maincavi-esaresuspendedforvibra-onisola-ontodecreasetheunitygainfrequency(UGF)oftheirservo(~afew10Hz).

•  (Ifpossible)usenewdigitalcontrolsystem.

PointsinPhase-1


Moku:Lab

hrp://www.liquidinstruments.com ←VenturefromANU


Moku:Lab

hrp://www.liquidinstruments.com

NOTE:IfweuseMoku:Labincontrolservo,thefrequencyrangeisabout1MHzbecauseof-medelayalthoughsamplingfrequencyismushhigher.


•  Howtoaligntheop-calzenithangle?•  Canweachievethever-caldoubleop-calspringwherethecavi-esdon’tsharetheop-calpath?

•  Howtodecouplethetwomaincavi-esfromtheother?

•  Howtosupportthelevita-ngmirrorbeforelevita-on?

•  Howtoknowthemirrorislevitated?•  Howtosuspendtheop-calbenchonwhichthemaincavi-esare?

Problems(?)inPhase-1








Zenithanglemisalignmenteffect

mgsinθ

~0.1um~w0/10

~0.5mm

0.2deg



Zenithanglealignment

• 2つの錘を吊るした紐がアイリスを通るようにする • アイリスに通るように上下の入射光軸をアライン • 入射光が浮上鏡の中心(~重心)に当たるよう配置 • 上下共振器の共振が取れるように各鏡をアライン • 移動させても、再び紐がアイリスを通るよう光学系全体の水平度を調整すればよいだけ

アラインメント手順案

18 入射光軸 // 重力入射光軸 // 共振器軸入射光軸上に重心

2mm

50cm

2e-3/0.5=4e-3rad~0.2deg



•  Useaccelerometerandgyrosensor.– Accelerometercandetectthegravitydirec-on.– Gyrosensorcandetecttheangledisplacement.

•  Comparetheop-calcavityaxiswiththestringofplumb.–  SeethetransmiredlightaxiswithIRcameraandscareringsomething.

Otherchoicestoalignop-calzenithangle

!a

scarering








Doubleop-calspring

-Ordinarycase

-Sandwichcase


•  Coupledcasewasdemonstrated.

Doubleop-calspring

N.Gordon+,“Experimentaldemonstra-onofcoupledop-calsprings,”CQG(2017)

10mprototypeinGlasgow








Decouplingtwomaincavi-es

orLossy

eg)Thorlabs:high-powercubePBS(PBS12-1064-HP),T=0.988

-CanweuseprisminsteadofPBS?

eg1)Thorlabs:platePBS(PBSW-1064),Tp=0.993,Ts=0.0055(1-Ts=0.9945)

eg2)Thorlabs:plateFPB(FPB1059-43),Tp=0.992,Ts=6e-5(1-Ts=0.99994)








Levita-ngmirrorsupport

-Ontorsionpendulum -Onfixedstage


•  Advantageoftorsionpendulum– mirrorposi-oncanbeadjusted.–  ver-calandhorizontalop-calspringeffectcanbemeasured.

•  Disadvantageoftorsionpendulum– mirrorposi-onisnotstablewithoutcontrol.–  requirementformirrordisplacementRMS

•  ver-cal:<<50pm(freerun:50um)•  horizontal:<<0.6um(freerun:1mm)

–  verystrongservocontrolanddampingisrequired.–  lownoisesensingforrollisalsorequired.

Levita-ngmirrorsupport


•  Sensingmethodoftorsionpendulum

Auxiliarycavity

roll(ver-cal):cavity

magnet

long.(horizontal):photosensor

yaw(horizontal):op-callever

foractua-on(coilmagnet)

fordamping(coil(resistor)magnet)

Auxiliarycavity

trans.(horizontal):photosensor








•  Whenthemirrorlevitate,themirror’smechanicalresponseshouldchangedrama-cally.Thus,wecanknowthemirrorlevita-onbymeasuringtheopenlooptransferfunc-on.

•  Moreover,ifweaddthelinesignalintothePZTonwhichthemirroris(ortheaux.cavityincidentlightpower)andshakethemirror,– whenthemirrorisnotlevitated,thesignalcanbedetectedwiththemaincavity

– whenthemirrorislevitated,thesignalcanNOTbedetectedwiththemaincavity

Howtodetectthemirrorlevita-on








Bladespringorspring?

-Bladespring -Spring

or

-Targetresonantfrequencyis1Hzforhorizontalandver-cal.


•  Notconsideredproblems–  Howtomakeastabledetuning.–  Vacuumsystem.

•  Todo–  Buildlaserpoweramplitudesystem.–  Makefreq.referenceforfreq.stabiliza-on.–  DesignLSS,suspension,op-csarrangement.–  (Buildnewdigitalsystem.)

•  Tobuy–  Fiberop-cscompa-blewith1064-nmlaser.

•  fiber(coveredandbare),EOMx2,AOMx2,fiberop-cs(BS,collimator,FI,andsoon),fiberfeedthrough,fiberamp.,(lasersource?),andsoon.

–  Cavitymirror(formainandaux.)–  Suspensionsystemandop-calbench.

OtherthingsinPhase-1






Schedule


4 6 8 10 12 2 4 6 8 10 12 2 4 8 12 3

Phase-0

Phase-1

Phase-2

Phase-3


theore-calstudy

hor.stab.demo.


aux.cavitystudy


(3m)

(6m)(6m)

modifydesign

buynewmir.(1m)


check1.6-mgmir.

(6m)

reachSQL!!

writepaper

re-buildsetup(6m)


(2m) writepaper

writepaperbuyitems


writethesis

writepaper:deskwork



Experimentalconfigura-oninPhase-2-wavelength:1064nm-finesse:100(lower,upper)-inputpower:10W(lower)

2.1W(upper)-lev.mirrormass:0.2mg-int.reflec-vity:0.975(lev.)

0.962(l,u)-freq.ref.:asymmetricFMI

-Passivestabilizingcavity(doublepass)--length:3m(FSR:100MHz)--finesse:3x104--cavitypole:1.6kHz--Intracavitypower:~300kW!!


Sensi-vityinPhase-2

102 103 104 105 106

Frequency [Hz]

10-20

10-19

10-18

10-17

10-16D

ispl

acem

ent n

oise

spe

ctru

m [m

/rtH

z] SQLquantum noisecoating thermalsubstrate thermalresidual gas thermalfrequency noiseseismic


•  Usenew0.2-mgmirror.•  Use100-masymmetricfiberMichelsoninterferometer(AFMI)forfrequencystabiliza-onaround10kHz.

•  Usepassivelaserstabilizingcavity(PSC),thatisthecavitywithlowcavitypole(~1kHz).

•  Togeteffec-ve(2ndorder)passivelaserstabiliza-on,thetransmiredlightisreflectedbacktothePSC.(Double-passconfigura-on)

PointsinPhase-2


•  Such(0.2-mg)smallmirrorcanbemade?•  Isthefrequencystabiliza-onusingAFMIat10kHzpossible?

•  Circula-ngpowerinthePSCismorethan100kWwhichcouldburnitsmirrors.

•  EffectofthedisplacementofPSContheeffectofthepassivestabilizingshouldbeconsidered.

•  Sincecavitypoleofmaincavi-esisveryhigh(~8MHz),RFsidebandcanenterthecavi-estosomeextent.

•  IsthereanysciencewhichcanbedoneusingonlyonecavityreachingSQL?

ProblemsinPhase-2







ProblemsinPhase-2


•  Assmallaspossiblemirrorisberer.•  About1-mgmirrormaybeupperlimit,consideringfeasibleincidentpower(lower:40W,upper:12W,finesse100).

Massoflevitatedmirror

102 103 104 105 106

Frequency [Hz]

10-20

10-19

10-18

10-17

10-16

Dis

plac

emen

t noi

se s

pect

rum

[m/rt

Hz] SQL

quantum noisecoating thermalsubstrate thermalresidual gas thermalfrequency noiseseismic







ProblemsinPhase-2


AFMIvsReferencecavity

or

K.Nagano,Masterthesis,UniversityofTokyo(2017)

S(?).Takahashi,Masterthesis,UniversityofTokyo(2008)


•  Requirementofthefrequencynoiseis1x10-4Hz/rtHzat10kHz.

•  Fortheac-vestabiliza-on,itisrelaxedtobe~5x10-3Hz/rtHzat10kHzthankstothePSC.

•  Displacementsensi-vityrequirement.– ForAFMI(with100-masymmetry)

•  xAFMI=1.7x10-15m/rtHz– Forreferencecavity(cavitylength20cm)

•  xRC=3.3x10-18m/rtHz– Suspendedmirrorcavity(likeKAGRA’sinputmodecleaner)canbeused?

AFMIvsReferencecavity


AsymmetricfiberMIsensi-vity

NOTE:Inthismeasurement,lasersourcewas1550-nmDFBfiberlaser,whichmaybemorenoisythan1064-nmNPROlaser.

S(?).Takahashi,Masterthesis,UniversityofTokyo(2008)

NOTE2:Asymmetrywas100m.


AsymmetricfiberMIsensi-vity

NOTE:Inthismeasurement,lasersourcewas1540-nmRIOfiberlaser,whichismorenoisythan1064-nmNPROlaser.

R.Šmíd+,“FrequencyNoiseSuppressionofaSingleModeLaserwithanUnbalancedFiberInterferometerforSubnanometerInterferometry,“Sensors(2015)

NOTE2:Asymmetrywas2.09km.







ProblemsinPhase-2


•  Circula-ngpowerinPSCwillbeverylarge,morethan100kW.–  Forexample,circula-ngpowerinKAGRA’sPMCwithhighpower(~100W)laserislessthan10kW.

– Withpulselaser(10psand250MHzrepe--onrate),670kWofaveragepowerwasdemonstrated.

•  IsitOK?Orcanweresolveit?– Makebeamsizelarge?(smallerintensity)– Makelongercavity?(smallerfinesse)–  Coolthecavitywithliquidnitrogen?

•  Anyway,verycarefultreatmentisrequiredtoavoidcontamina-on,forexampledust.

Circula-ngpowerinPSC

H.Carstens+,Opt.Ler.(2014)







ProblemsinPhase-2







ProblemsinPhase-2







ProblemsinPhase-2


•  Allscienceideasusingop-callevita-onwhichIhavesofarrequiretwocavi-esreachingSQL.

•  However,ittakesalotof-meandefforttobuildanothercavity.

•  ThusI’dliketodosomescien-ficworkswithonlyonecavityreachingSQL.

•  Ibelieveinteres-ngsciencemustexist.•  Ifyouhaveanyidea,pleaseshareitwithme.

Scienceofop-callevita-onexperiment


•  Notconsideredproblems– Theeffectoftheuppercavity’sradia-onpressurenoise.

•  Todo– Designsuspension,op-csarrangement.– Discussthepossibilityofthesmallmirrorwithmanufacturingcompany(Sigma,LMS,…).

•  Tobuy– Newsmallmirror,cavitymirrors.

OtherthingsinPhase-2


Conclusion


4 6 8 10 12 2 4 6 8 10 12 2 4 8 12 3

Phase-0

Phase-1

Phase-2

Phase-3

SummaryH29 (D1) H30 (D2) X (D3)

theore-calstudy

hor.stab.demo.


aux.cavitystudy


(3m)

(6m)(6m)

modifydesign

buynewmir.(1m)


check1.6-mgmir.

(6m)

reachSQL!!

writepaper

re-buildsetup(6m)


(2m) writepaper

writepaperbuyitems


writethesis

writepaper:deskwork



End

Documents

Future prospects of the op-cal levita-on experiment · 2017-04-28 · Future prospects of the op-cal levita-on experiment ( ) KAGRA observatory, Ins-tute for cosmic ray research,