Current Progress of Development of Laser Interferometry for LISA-type Mission in China
Hsien-Chi Yeh
School of PhysicsHuazhong University of Science & Technology
Gravitational Waves: New Frontier16-18 January, 2013
Research Park, Seoul National University, KOREA
Outline
11 Motivation and Strategy
22
Current Progress at HUST33
Scheme and Error Budget
Roadmap and Conclusion44
Orbit precession in the perihelion o
f planets Deflection of light by solar gravity Redshift of spectral lines Frame dragging
Gravitational waves
Motivation: Gravitational Waves Detection in
Space
Direct Measurement of Gravitational Waves
LIGO Hanford Observatory
Baseline: 4 kmStrain sensitivity: ~10-22/Hz1/2
Sensing frequency: 40 ~ 10kHz
Baseline: 5106 kmStrain sensitivity: ~10-22/Hz1/2
Sensing frequency: 10-4 ~ 0.1Hz
LISA Space Antenna
eLISA/NGO & LISA Pathfinder
• Arm length: ~106km• Duration: 2 years (total 4 ye
ars)• Interferometry: 18pm/Hz1/2
• Residual acceleration (Drag-Free): 310-15 m/s2/Hz1/2
Frequencyrange (Hz)
Arm lengthDisplacement
noise (pm/Hz1/2)Acceleration noise
(ms-2/Hz1/2)
LISA 10-4 ~ 10-1 5109 m ~ 20 310-15 @1mHz
ALIA 10-3 ~ 1 ~ 5108 m ~ 0.1 ~ 510-14@10mHz
ASTROD 10-6 ~ 10-3 ~ 31011 m ~ 2000 ~ 810-16 @0.1mHz
10-18
10-19
10-20
10-21
10-22
10-23
10-24
10-25
LIGO
A-LISA (ALIA)(LISA type, 5105km)
ASTROD(2A.U.)
10-5 10-4 10-3 10-2 10-1 100 101 102 103
Sensitivity Requirements of GWD Missions
KAGRA
Strategy: Treat SAGM as LISA Pathfinder
Satellite-to-satellite tracking:• Separation: 50~200 km• Altitude: 250~400 km• Drag-free control: 10-11 m/s2/Hz1/[email protected]• Measurement:
Laser ranging (range: 30~50 nm, range-rate: < 100 nm/s)GPS (~1 mm)
GRACE-like mission
Space Advanced Gravity Measurements (SAGM)
Schematics of Inter-Satellite Laser Ranging
200km
BeamCollimation & Pointing
Control
ProofMass
Inertial Sensor
Inertial Sensor
HeterodyneLaser
Interferometer
Satellite Platform
EnvironmentControl
Dra
g F
ree
Con
trol Beam
Collimation & Pointing
Control
ProofMass
Inertial Sensor
Inertial Sensor
TransponderWith Phase-Locked Loop
Satellite Platform
EnvironmentControl
Dra
g F
ree
Con
trol
PMOBOPLLM
DUSOM
Lc
Ltc
L
2)(2
Error Source Error component
Pre-stabilized laser: f < 50 Hz/Hz1/2
L = 200 km 30.0 nm/Hz1/2
Thermal drift of O.B. (fused quartz):thermal variation: 0.01Kunbalanced OPL: 1 cm
4.0 nm/Hz1/2
Divergence angle of laser beam:div ~ 3.510-5 rad
Pointing control:dc ~ 10-5 rad, jit ~ 10-5 rad/Hz1/2
9.0 nm/Hz1/2
Phasemeter resolution 1.0 nm/Hz1/2
Residual error of OPLL 3.0 nm/Hz1/2
Coupling error between OB and PM 5.0 nm/Hz1/2
Shot noise and Ionosphere effect < 0.1 nm
(RSS) Total ~ 32 nm/Hz1/2
Error Budget of Laser Ranging
10-m Prototype of Laser Ranging SystemInstalled at HUST (2009~2010)
5-nm stepDriving by PZT stage
FPGA-Based Digital Phasemeter (2010~2011)
1200 1220 1240 1260 1280 1300
-3.21
-3.208
-3.206
-3.204
-3.202
-3.2
-3.198
-3.196
-3.194
Time origin: 2011-06-15 17:30:00.000
Ph
ase
[deg
]
Time [s]
1.txt_01
50MHz clock
Noise level: ~10-5 rad/Hz1/[email protected]
Numerical ControlOscillator
Downsampling
LPFilter PIADC
Freq./Phaseoutputs
Disp.Speed
Anti-AFilter
Input
Ultra-Stable Optical Bench (2011-2012)
Cooperation with AEI, Hannover
0 0.2 0.4 0.6 0.8 1-60
-40
-20
0
20
40
60
80Time origin: 2012-04-10 04:00:00.000
Dis
pla
cem
en
t [p
m]
Time [s]
PZT-4mVpp-step data after fitted polynomial taken out
Above data after smoothing with 4-point averageamplitude: 25 pm
10-2
10-1
100
101
10-11
10-10
10-9
10-8
10-7
10-6
10-5
Accele
rati
on
LA
SD
[m
/s2 ]/H
z1/2
Frequency [Hz]
OB106-EastOB106-NorthOB106-VerticalInterferometer
Transponder-Type Laser Ranging (2012)
ProofMass
OpticalBench
ProofMass
OpticalBench
PhaseMeter
PhaseLockedControl
Master
laser
Slave
laser
Displacement output
PZT
1784 1785 1786 1787 1788 1789 17903.7646
3.7647
3.7648
3.7649
3.765
3.7651
3.7652x 10
4 Time origin: 2011-12-31 20:40:00.000
Dis
pla
cem
en
t [
nm
]
Time [s]
Displacement data with 1nm amplitude 1Hz sinewaveDisplacement data after filtered
Weak-light: 100 nW
Homodyne OPLL
1-nm sinusoidal motion
F-P cavity forfrequency stabilization
Laser Frequency Stabilization
NISTNPL
NASA
PDH scheme
HUST
Beam Pointing Angle Measurement
Phase-difference Measurement• Divergence angle: 3.510-5 ra
d• Received power: 10-7 W• Phase difference misalignme
nt angle• precision: 10-7 rad
Contrast Measurement• Divergence angle: 10-4 rad• Received power: 10-8 W• Contrast misalignment angle• precision: 10-5 rad
2/)( BA
BA
II
IIcontrast
Proof Mass & Capacitive Sensor
• 6-DOF• Sensitivity: 10-6 pF/Hz1/2
• FPGA-based electronics
Multi-Stage Pendulum for Performance Test
Preliminary Test Result of Accelerometer
Noise level: ~10-10 m/s2/Hz1/[email protected]
testing system
2010 20202015 2025 2030
Inter-Satellite Laser RangingFor Earth’s Gravity Recovery• Inter-satellite distance: 50-200 k
m• Sensitivity: 30-50 nm/Hz1/2
• Transponder-type heterodyne interferometry
• Drag-free control: 10-11 m/s2/Hz1/2
@0.1Hz• Pointing control: 10-6 rad/Hz1/2
Inter-Satellite Laser Interferometer
For Gravitational Waves Detection
• Inter-satellite distance: 105~106 km
• Sensitivity: < 1 pm/Hz1/2
• Transponder-type heterodyne interferometry
• Drag-free control: 10-14 m/s2/Hz1/2
@0.1Hz• Special methods to decompress l
aser frequency noise• Pointing control: 10-9 rad/Hz1/2
Proposed Timeline
• GW detection (long-term goal)Earths gravity recovery (short-term goal):SAGM as our LISA Pathfinder
• Preliminary demonstration:(1) nanometre-level transponding laser ranging with 100-nW weak-light phase locking(2) 6-DOF electrostatic inertial sensor
• Focused tasks in the next step: (1) space-qualified frequency-stabilized laser(2) laser beam pointing measurement and control(3) simulation experiment of plasma in ionosphere (4) ultra-precision inertial sensor and proof mass
Conclusions
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Center for Gravitational Experiments
• Atom-interferometry-based standard of g
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• Cold-atom physics• Optical frequency standard & las
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