L S f S di L G id S f TMTLaser System for Sodium Laser ...ctmt.bao.ac.cn/CTMTColloquium2011/poster_presentation/Na-LGS-T… · Laser System for Sodium Laser Guide Star of TMTLaser

L S f S di L G id S f TMTL S f S di L G id S f TMTLaser System for Sodium Laser Guide Star of TMTLaser System for Sodium Laser Guide Star of TMTLaser System for Sodium Laser Guide Star of TMTLaser System for Sodium Laser Guide Star of TMT

Bo YongBo YongBo YongBo Yong

Research Center for Laser Physics & Technology (Research Center for Laser Physics & Technology (Laser CenterLaser Center))Research Center for Laser Physics & Technology (Research Center for Laser Physics & Technology (Laser CenterLaser Center))

Technical Institute of Physics and Chemistry (Technical Institute of Physics and Chemistry (TIPCTIPC))Technical Institute of Physics and Chemistry (Technical Institute of Physics and Chemistry (TIPCTIPC))

Chinese Academy of Science (Chinese Academy of Science (CASCAS))Chinese Academy of Science (Chinese Academy of Science (CASCAS))

2525--0505--201120112525--0505--201120111

Laser System for Sodium Laser Guide Star of TMTLaser System for Sodium Laser Guide Star of TMTLaser System for Sodium Laser Guide Star of TMTLaser System for Sodium Laser Guide Star of TMT

OutlineOutlineOutline Outline 11 Introduction ofIntroduction of Sodium Laser Guide StarSodium Laser Guide Star1.1. Introduction of Introduction of Sodium Laser Guide StarSodium Laser Guide Star

22 L S t f TMT LGSF R i tL S t f TMT LGSF R i t2.2. Laser System of TMT LGSF RequirementsLaser System of TMT LGSF Requirementsy qy q

33 Development of Our Sodium Laser SystemDevelopment of Our Sodium Laser System3.3. Development of Our Sodium Laser SystemDevelopment of Our Sodium Laser System

44 S h d l f R&D f O L S tS h d l f R&D f O L S t4.4. Schedule of R&D for Our Laser SystemSchedule of R&D for Our Laser Systemyy

LGSFLGSF Laser Guide Star FacilityLaser Guide Star FacilityLGSF LGSF -- Laser Guide Star FacilityLaser Guide Star Facility

2

1 Introduction of1 Introduction of Sodium Laser Guide StarSodium Laser Guide Star1. Introduction of 1. Introduction of Sodium Laser Guide StarSodium Laser Guide Star

To correct the wavefront distortions byTo correct the wavefront distortions byAdaptive opticsAdaptive optics

To correct the wavefront distortions by To correct the wavefront distortions by t h i t b l d i tht h i t b l d i thAdaptive optics Adaptive optics

i id ti id tatmospheric turbulence and improve the atmospheric turbulence and improve the

using guidestarsusing guidestars image quality of telescopes to diffraction Limitimage quality of telescopes to diffraction Limitus g gu des a sus g gu des a s image quality of telescopes to diffraction Limit image quality of telescopes to diffraction Limit

NGS

N t l id tN t l id t NGSNGSNGSspace objects

Natural guide star Natural guide star -- NGSNGSggSodium layer

Sky coverage is less than 1% ~100kmy gSodium LGS

Laser guide starLaser guide star -- LGSLGSLaser guide star Laser guide star -- LGSLGSperfect star - altitude of 100km Wavefrontperfect star - altitude of 100km Wavefront

detector

Created by exciting atomic atomospheric Created by exciting atomic sodium at its strong D2a

pturbulence

sodium at its strong D2a D f blabsorption line of 589.159nm in Deformable

M irror absorption line of 589.159nm in the upper atmospheres (85 0kmthe upper atmospheres (85- 0km

105km))Image

3TelescopeSodium laser Image

Telescope

1 Introd ction of1 Introd ction of Sodi m Laser G ide StarSodi m Laser G ide Star1. Introduction of 1. Introduction of Sodium Laser Guide StarSodium Laser Guide Star

Sodium layer measured in KickSodium layer measured in Kick

Atoms in theAtoms in the WavelengWaveleng DensityDensity Cross sectionCross section Density* CrossDensity* CrossAtoms in the Atoms in the WavelengWaveleng DensityDensity Cross sectionCross section Density* Cross Density* Cross upper atmosphersupper atmosphers (nm)(nm) (cm(cm--3 3 )) ( 10( 10--1212cmcm2 2 )) section ( 10section ( 10--99cm )cm )upper atmosphersupper atmosphers (nm)(nm) (cm(cm )) ( 10( 10 cmcm )) sect o ( 0sect o ( 0 c )c )

NaNa 589.159589.159 50005000 1515 7575aa 589 59589 59 50005000 55 55

FeFe 372 0372 0 30003000 1 01 0 3 03 0FeFe 372.0372.0 30003000 1.01.0 3.03.0

CaCa 422 7422 7 100100 3838 3 83 8CaCa 422.7422.7 100100 3838 3.83.84

2. Laser System of TMT LGSF Requirements2. Laser System of TMT LGSF Requirements2. Laser System of TMT LGSF Requirements2. Laser System of TMT LGSF Requirements

Laser launch Laser launch LGSFLGSF--------------Laser launch Laser launch t lt l

LGSFLGSFL idL idtelescopetelescope Laser guide Laser guide pp ggstar facilitystar facilitystar facilitystar facility

Beam Beam Beam Beam asterismtransfer transfer

asterism

opticsopticsopticsopticsTo increase theTo increase the fi ld f i ltifield of view, multi-conjugatej gadaptive opticaladaptive optical (MCAO) systems(MCAO) systems will be used which

Sodium laser Sodium laser need multiplesystemssystems

need multiple guidestars by systemssystemsguidestars by multiple laser psystems.

5systems.

Fi TMT LGSF El i J l fi i i l lFi TMT LGSF El i J l fi i i l lFig. TMT LGSF Elevation Journal configuration optical layoutFig. TMT LGSF Elevation Journal configuration optical layoutg g p yg g p y

Sodium laser systemSodium laser systemBeam transfer opticsBeam transfer opticsLaser launch telescopepL f t tLaser safety system

Work can be done by ourWork can be done by our Laser Center TICP CASLaser Center, TICP, CAS


Laser Power RequirementsLaser Power Requirements“The NFIRAOS asterism consists of six 25W-LGS, therefore a total of at leastThe NFIRAOS asterism consists of six 25W LGS, therefore a total of at least150W i i d d h NFIRAOS i ”150W is required to produce the NFIRAOS asterism”“Each individual Laser Head shall provide a coupling efficiency of atEach individual Laser Head shall provide a coupling efficiency of atleast 130 photons-m2/s/W/ion with the mesospheric sodium layer”p p y

Specifications of each laser unitSpecifications of each laser unit

Output power : > 25 WOutput power : > 25 W

Wavelength : Na-D2a line FWHMWavelength : Na-D2a line FWHMLinewidth : < 1.2 GHzLinewidth : 1.2 GHz

Beam quality: ~1 DLq y

Polarization: > 98%

* DL - Diffraction Limit7

Linewidth of Na D2 linesLinewidth of Na D2 lines DL Diffraction Limit

Linewidth of Na D2 linesLinewidth of Na D2 lines


Development status of sodium lasersDevelopment status of sodium lasers

LasersLasers TechniquesTechniques characteristicscharacteristicsLasersLasers TechniquesTechniques characteristicscharacteristics1064nm & 1319nm SFG1064nm & 1319nm SFG1064nm & 1319nm SFG1064nm & 1319nm SFG

DiodeDiode-- CW 50W achieved in USACW 50W achieved in USA1064nm1064nm＋＋RamanRaman＋＋DiodeDiodedd

CW 50W achieved in USACW 50W achieved in USA1064nm1064nm＋＋RamanRaman＋＋ff d blid blipumped pumped Operation modeOperation mode：：cw cw / / μμs / pss / psfrequencyfrequency--doublingdoubling

solidsolid--statestatepp μμ ppq yq y gg

1064 f1064 f d blid blisolidsolid state state laserlaser

1064nm frequency1064nm frequency--doubling doubling laserlaser RamanRaman

RR ＋＋ ff d blid bli CW 50W hi d i GCW 50W hi d i GRamanRaman＋＋ frequencyfrequency--doubling doubling CW 50W achieved in GermanyCW 50W achieved in GermanyFiber laserFiber laser

q yq y gg yyOperation modeOperation mode cwcw938938 ＋＋15831583 SFGSFGFiber laserFiber laser Operation modeOperation mode：： cwcw938nm938nm＋＋1583nm1583nm SFGSFG

11781178 ＋＋ff d blid bli1178nm1178nm＋＋frequencyfrequency--doublingdoublingq yq y ggD lD l 532532 d RD6Gd RD6G Hi h i diffi ltHi h i diffi ltDye laserDye laser 532nm532nm pumped RD6Gpumped RD6G High power is difficultHigh power is difficultG lG l NN B d l iB d l iGas laserGas laser Na vaporNa vapor Be developingBe developing

8

3 D l t f di l t3 D l t f di l t3. Development of our sodium laser system3. Development of our sodium laser systemp yp y

ii ii f AGf AGDiodeDiode--pumped solidpumped solid--state sumstate sum--frequency Nd:YAG laser systemfrequency Nd:YAG laser systemp pp p q y yq y y

10641064nmnm NdNd::YAGYAG MOPAMOPA LaserLaser10641064nmnm NdNd::YAGYAG MOPAMOPA LaserLaserSFGSFG 589589SFGSFG＝＝>>589589nmnm outputoutputpp

13191319nmnm NdNd YAGYAG MOPAMOPA LaseLase13191319nmnm NdNd::YAGYAG MOPAMOPA LaserLaser

Operation mode:Operation mode:Operation mode:Operation mode:

μμss level pulse laserlevel pulse laserμμss--level pulse laserlevel pulse laserμμ pp

9

3 Development of our sodium laser system3 Development of our sodium laser system3. Development of our sodium laser system3. Development of our sodium laser system

Advantage of aAdvantage of a μμss pulsed laserpulsed laser-------- Advantage of a Advantage of a μμss--pulsed laserpulsed laser105km105km

S diS di105km105km

AA μμss--pulse laser for generating sodiumpulse laser for generating sodium SodiumSodiumA A μμss pulse laser for generating sodium pulse laser for generating sodium LGS id bl l fLGS id bl l f beaconbeaconLGS can provide a gatable pulse formatLGS can provide a gatable pulse format beaconbeacon

85k85kp g pp g p

To eliminate the Rayleigh backscatterTo eliminate the Rayleigh backscatter 85km85kmTo eliminate the Rayleigh backscatter To eliminate the Rayleigh backscatter effects and fratricide between the multipleeffects and fratricide between the multipleeffects and fratricide between the multiple effects and fratricide between the multiple

id tid tguidestarsguidestarsggT li i t l id t l tiT li i t l id t l tiTo eliminate laser guide star elongation To eliminate laser guide star elongation g gg g

by tracking (or focusing on) short laserby tracking (or focusing on) short laserby tracking (or focusing on) short laser by tracking (or focusing on) short laser pulsespulsespp

““O h l h l i (O h l h l i ( l dl d RayleighRayleigh““Other laser technologies (Other laser technologies (μμss--pulsed pulsed y gy gbackscatterbackscatter

g (g (μμ pplaserslasers msms p lsed lasers) not c rrentlp lsed lasers) not c rrentl backscatterbackscatterlasers, lasers, msms--pulsed lasers) not currently pulsed lasers) not currently available at or near TMT power level”available at or near TMT power level”available at or near TMT power levelavailable at or near TMT power level

10L id tL id tLaser guide starLaser guide star


Current specifications of our laser systemCurrent specifications of our laser system-------- Current specifications of our laser systemCurrent specifications of our laser system

19-12-2009 to 30-09-201019 12 2009 to 30 09 2010

O t t 33 W Output power : >25 WOutput power : 33 W Output power : >25 W

W l th N D li W l th N D liWavelength : Na D2a line Wavelength : Na D2a line

Li idth 0 4 GH Li idth < 1GHLinewidth : 0.4 GHz Linewidth : < 1GHz

B li M2 1 2 B lit 1DLBeam quality: M2=1.2 Beam quality: ~1DLq yP l i i 98%Polarization: 99% Polarization: > 98%

i i 00Repetition rate: 500 Hz Repetition rate: ~500 Hzp p

Pulse width: 120 μs Pulse width: ~120 μsμ μ

Specifications of our laser systemSpecifications of our laser system TMTTMT--LGSFLGSF primaryprimary requirementsrequirementsp yp y TMTTMT LGSF LGSF primary primary requirementsrequirements

11


S ifi ti f l tS ifi ti f l t---- Specifications of our laser systemSpecifications of our laser systemSpec cat o s o ou ase systeSpec cat o s o ou ase syste

Output power of our laser systemOutput power of our laser systemOutput power of our laser systemOutput power of our laser system

Sodium laser1319nm1319nm

1064nmi

589prism

589nm

P tPow er meter

33 W at 589nm33 W at 589nm33 W at 589nm33 W at 589nm

12


B lit f l tB lit f l t---- Beam quality of our laser systemBeam quality of our laser systemq y yq y y

M2 1 20M2X 1.20X

M2 1 20M2Y 1.20

at 33 Wat 33 Wat 33 Wat 33 W

Beam quality measured by beamBeam quality measured by beamM2-200 of Spiricon Inc USA Beam quality measured by beam Beam quality measured by beam lit l flit l f M2 200

M -200 of Spiricon Inc., USA 13quality analyzer of quality analyzer of M2-200

3 Development of our sodium laser system3 Development of our sodium laser system3. Development of our sodium laser system3. Development of our sodium laser system---- Specifications of our laser systemSpecifications of our laser systemSpecifications of our laser systemSpecifications of our laser system

Wavelength and Wavelength and linewidthlinewidth measured by laser measured by laser gg yywavelength meter WSwavelength meter WS--7L7Lwavelength meter WSwavelength meter WS 7L7L

LinewidthLinewidthLinewidth Linewidth 33 W33 Wat 33 Wat 33 Wat 33 Wat 33 W

< 0 7GHz< 0 7GHz< 0.7GHz< 0.7GHz

WS 7L of HighFinesse IncWS-7L of HighFinesse Inc., GGermany

14


Wavelength calibration for laser system using a NaWavelength calibration for laser system using a Na--lamplampg y gg y g pp

S di l l i lSodium laser pulse signal

μs-pulse: 500Hz, 120μsNa resonant fluorescence signal

μs pulse: 500Hz, 120μsg

N l th lib t Na resonant fluorescence signal on oscillographNa wavelength calibrator Na resonant fluorescence signal on oscillographfabricated by our lab

15y


Wavelength calibration for laser system using a Na vaporWavelength calibration for laser system using a Na vaporWavelength calibration for laser system using a Na vaporWavelength calibration for laser system using a Na vapor

1 001.00

tyns

it

0 95nten 0.95

e in

nce

cen

0 90resc

0.90uo

rl f

lum

al

0.85orm

0.85

No

508.844 508.846 508.848 508.850 508.852Laser frequency (Hz)Na resonant fluorescence by CCD Laser frequency (Hz)y

Na fluorescence intensity vs laser frequencyNa fluorescence intensity vs laser frequency16


““TheThe workwork--packagepackage ““TIPCTIPCThe The workwork package package TIPC TIPC Laser Prototype Study forLaser Prototype Study forLaser Prototype Study for Laser Prototype Study for the TMT”the TMT” waswas signsignededthe TMT” the TMT” was was signsignededb tb t NAOC/TIPCNAOC/TIPC dbetween between NAOC/TIPCNAOC/TIPC and TMT on Jan,on Jan, 20112011TMT on Jan,on Jan, 20112011

T d l 20W l lT d l 20W l lTo develop a 20W level To develop a 20W level ppdi l t tdi l t tsodium laser prototypesodium laser prototypep ypp yp

17

3 Development of our sodium laser system3 Development of our sodium laser system3. Development of our sodium laser system3. Development of our sodium laser system---- our laser prototypeour laser prototypeour laser prototypeour laser prototype

Engeneering assembling drawingEngeneering assembling drawing

h l d hThe prototype was completed on March, 2011p yp p ,

18Laser prototype: 1200mmLaser prototype: 1200mm××900mm900mm××220mm 100kg220mm 100kgLaser prototype: 1200mmLaser prototype: 1200mm××900mm900mm××220mm, ~100kg220mm, ~100kg


Sodium LGS generation by our laser prototypeour laser prototype---- Sodium LGS generation by our laser prototypeour laser prototype

~100km Sodium LGS~100km Sodium LGS

Sodium LGS generating Sodium LGS generating g gg g

h th l l thh th l l thwhen the laser wavelength when the laser wavelength

on Na D2a lineon Na D2a lineon Na D2a lineon Na D2a line

RayleighRayleighRayleighRayleighb k ttb k ttbackscatterbackscatter

Sodium laserSodium laserSodium laser Sodium laser LaunchLaunch Receiver &Receiver &systemsystem

LaunchLaunchtelescopetelescope

Receiver & Receiver & i i ti i tsystemsystem telescopetelescope imaging systemimaging system

19

3 Development of our sodium laser system3 Development of our sodium laser system3. Development of our sodium laser system3. Development of our sodium laser systemp yp y

Fi ld i t f th LGS tFi ld i t f th LGS t Laser wavelengthField experiment for the LGS systemField experiment for the LGS system Laser wavelength Sodium laser system made in TIPC CAS on Na D2a lineSodium laser system made in TIPC, CAS o N e

S di LGSS di LGSSodium LGSSodium LGS

Launch telescope and Receiver & Laser wavelengthLaunch telescope and Receiver & Laser wavelength NOT N D liimaging system made in IOE, CAS NOT on Na D2a lineg g y ,

RayleighRayleighRayleighRayleighbackscatterbackscatterbackscatterbackscatter

20W20W output to generate 8 7 magnitudeoutput to generate 8 7 magnitude2020W20W output to generate 8.7 magnitudeoutput to generate 8.7 magnitude


S h d l f R&DR&D f l tl t---- Schedule of R&DR&D for laser systemlaser systemyy

2011-2012: Further Improvement of the first prototype,Further Improvement of the first prototype,2011 2012: Further Improvement of the first prototype, Further Improvement of the first prototype, the photon return experiment on the UBCthe photon return experiment on the UBCthe photon return experiment on the UBC the photon return experiment on the UBC LZT site in CanadaLZT site in CanadaLZT site in CanadaLZT site in Canada

2012-2015: Improvements onImprovements on eengineeringngineering of laserof laser2012 2015: Improvements on Improvements on eengineering ngineering of laser of laser system, fabrication and inspection of thesystem, fabrication and inspection of thesystem, fabrication and inspection of the system, fabrication and inspection of the prototype,prototype, the online testthe online test with the entirewith the entireprototype, prototype, the online test the online test with the entire with the entire

f i i i i ff i i i i fsystem, fabrication and inspection of system, fabrication and inspection of the the sys e , b c o d spec o osys e , b c o d spec o o eefi lfi lfinal prototypefinal prototypep ypp yp

2016-2018: Fabrication ofFabrication of sevenseven LGS laser systems, andLGS laser systems, and2016 2018: Fabrication of Fabrication of sevenseven LGS laser systems, and LGS laser systems, and li i i i h h ili i i i h h ionline integration with the entire systemonline integration with the entire systemg yg y

2019: Launching of the TMT system.Launching of the TMT system.2121

2019: Launching of the TMT system.Launching of the TMT system.

2222

Documents

L S f S di L G id S f TMTLaser System for Sodium Laser ...ctmt.bao.ac.cn/CTMTColloquium2011/poster_presentation/Na-LGS-T… · Laser System for Sodium Laser Guide Star of TMTLaser