Current Progress of Development of Laser Interferometry for LISA-type Mission in China Hsien-Chi Yeh School of Physics Huazhong University of Science &

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

Center for Gravitational Experiments

Lab. Area:： ~ 7000 m2

• Building: 2800 m2

• Cave lab.: 4000 m2

• Machining shop: 600 m2

-12 0 12 24 36 48 60 72 84 96 108120132144156

19.350

19.355

19.360

19.365

19.370

Tem

per

atu

re (

o C)

Time (hour)

Seismic vibrationTemp. variation

Professor: 12, Associate Professor: 3Lecturer: 4, Post-Doctor: 5Graduate students: ~ 60

Center for Gravitational Experiments

• Atom-interferometry-based standard of g

• Superconducting accelerometer• Electrostatic accelerometer• Calibration of weak force

• Cold-atom physics• Optical frequency standard & las

er frequency stabilization• Quantum-optic experiments

• Measurement of G constant• Test of Newtonian inverse-squar

ed law (torsion balance & AFM)• Test of Equivalence Principle• Laser interferometry for GW det

ection

Measurement of Gravity

AMO

Gravitational Physics

CG

E

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