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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
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 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
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
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
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
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
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
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
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
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
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 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
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 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
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
““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
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
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
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
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.