Development of laser interferometer
prototype used for satellite-to-satellite
displacement measurement
Gang Jin, Yuqiong Li, Yuhui Dong, Heshan Liu, Ziren Luo
Institute of Mechanics, Chinese Academy of Science, Beijing, 100190
10th LISA Symposium
Gainesville, May 19-23, 2014
Contents
• Motivation
• Introduction to SLI
 Constitution
 Key technologies
• SLI development in IMECH
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Phase-meter
Prototype of SLI
Beam pointing control
Phase locking
• Summary & outlooks
Motivation----detect G.W. in space
Gravitational Wave (G.W.)
direct prediction of general relativity
Low frequency G.W. sources (0.1mHz-1Hz):
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Go to space to avoid seismic noise
1~10 pm
Pioneer mission LISA (eLISA)
LISA type missions
• BBO
• DECIGO
• ALIA
• Chinese proposal (10mHz-1Hz)
Binary of super mass black holes
Extreme mass ratio in-spirals
Intermediate mass ratio in-spirals
Binary of compact objects
……
Detecting G.W. in space
----A bite of China
2008
IMRIs and binary of B.H.s
formed by Pop III stars[1]
2011
Technology demonstration mission
proposed, building prototypes
Official Chinese space G.W.
detection working group
constituted
2012
Institutes of CAS, Universities,
satellite companies
LISA X symposium
2014
Recent progress in China
Independent proposal
collaboration of space laser
interferometer G.W. detection
between CAS and ESA
IMECH assigned to build SLI
[1] Gong, Xuefei, et al. "A scientific case study of an advanced LISA mission."Classical and Quantum Gravity 28.9 (2011): 094012.
Introduction to SLI
----constitution
Heterodyne detection & non-Gaussian
profile weak light phase lock
20MHz, 10pw, top-hat beam profile, locking
precision10−5 𝑟𝑎𝑑/√𝐻𝑧
S.C.2
S.C.1
Million Kilometers
Introduction to SLI
----constitution
Hardware:
• Laser, pre-stabilized to 30𝐻𝑧/√𝐻𝑧;
• Interferometer, 1𝑝𝑚/√𝐻𝑧, 1𝑛𝑟𝑎𝑑/√𝐻𝑧;
• Telescope, 1𝑝𝑚/√𝐻𝑧, 1𝑛𝑟𝑎𝑑/√𝐻𝑧;
• Phase meter, 10−5 𝑟𝑎𝑑/√𝐻𝑧;
• Pointing ahead angle mechanism.
Introduction to SLI
----key technologies
Shot noise
Laser frequency noise
Clock jitter noise
Pointing jitter noise
Data pre-processing and
etc.
Big telescope, high laser power [1]
Pre-stabilization, arm-locking, TDI [2]
Sideband-sideband scheme [3]
Pointing control techniques [1]
Clock sync., ranging & laser comm. [1, 4]
[1] Danzmann K, Bender P, Brillet A, et al. LISA pre-phase A report[J]. Max-Planck-Institut fur Quantenoptik, Report MPQ, 1998, 208.
[2] Sheard B S, Gray M B, McClelland D E, et al. Laser frequency stabilization by locking to a LISA arm[J]. Physics letters A, 2003, 320(1): 9-21.
Tinto M, Estabrook F B, Armstrong J W. Time-delay interferometry for LISA[J]. Physical Review D, 2002, 65(8): 082003.
[3] Shaddock D A. Space-based gravitational wave detection with LISA[J]. Classical and Quantum Gravity, 2008, 25(11): 114012.
[4] Esteban J J, García A F, Barke S, et al. Experimental demonstration of weak-light laser ranging and data communication for LISA[J]. Optics
express, 2011, 19(17): 15937-15946.
Introduction to SLI
----to summarize
Methodology
• Heterodyne detection
• Top-hat beam profile weak light phase lock
Hardware
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Stable laser source
Ultra stable interferometer
Ultra stable telescope
High precision phase meter
Pointing ahead angle mechanism
Key technique
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Arm-locking
TDI
USO noise cancellation scheme
Pointing control techniques
Clock synchronization
Laser ranging
Interferometeric laser communication
SLI development in IMECH
---- A brief introduction
Funded by national
space science center
2010
Methodological demonstration:
homodyne V.S. heterodyne [1]
Funded by Chinese
Academy of Science
2012
building hardware, prototype
testing, technology development
LISA X symposium
2014
Recent status
[1] Yu-Qiong L, Zi-Ren L, He-Shan L, et al. Chinese Physics Letters, 2012, 29(7): 079501.
SLI development in IMECH
---- the interferometer
• Chinese space G.W. detector
• technology demonstration
mission
Chinese counterpart of LISA pathfinder
• Interferometer prototype
Noisy laser source: worse than 1MHz/√Hz
Achieve 100pm/√Hz, thermal noise dominates
Polarizing interferometer
Rectangular and straightforward
Fewer component
Equal arm-length
SLI development in IMECH
---- the phase meter
Based on FPGA
DPLL
4 channels
Signal frequency 1-2MHz
Output frequency >200Hz
LISA Symposium X, section Interferometry and Optics, Thursday, May 22nd, 17:15-17:30
SLI development in IMECH
---- the pointing control
Differential Wave Sensing [1]
Pointing control
demonstration
[1] Morrison E, Meers B J, Robertson D I, et al. Automatic alignment of optical interferometers[J]. Applied Optics, 1994, 33(22): 5041-5049.
LISA Symposium X, Poster Session Tuesday, May 20th, 15:45-17:30
SLI development in IMECH
---- the phase locking
Master laser
Interferometer
Phase
difference
Phase meter
Slave laser
Gaussian profile
1mW power
Locking precision mrad
Interferometer noise dominates
Summary & outlooks
• Heterodyne detection
• Top-hat beam profile weak light phase lock
• A
• N
Hardware
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Stable laser source
Ultra stable interferometer
Ultra stable telescope
High precision phase meter
Pointing ahead angle mechanism
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N
A
N
A
N
Key
technologies
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Arm-locking
TDI
USO noise cancellation scheme
Pointing control techniques
Clock synchronization
Laser ranging
Interfermeteric laser communication
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N
N
N
A
N
N
N
Methodology
Acknowledgement
• With special thanks to Gerhard Heinzel for his endless help in
almost everything of interferometer development;
• Thanks to Doc. Marina for her help of interferometer building;
• Thanks to Doc. Vitali for teaching us using IFOCAD;
• Thanks to Doc. Simon for sharing noise hunting experience;
• We also own many thanks to Albrecht Ruediger, Aiko
Samblowski, Yan Wang and many other AEI members for their
valuable helps.
Thank you all