Gang Jin, Yuqiong Li, Yuhui Dong, Heshan Liu, Ziren Luo

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 SymposiumGainesville, May 19-23, 2014

Contents• Motivation• Introduction to SLI

Constitution Key technologies

• SLI development in IMECH Phase-meter Prototype of SLI Beam pointing control Phase locking

• Summary & outlooks

Motivation----detect G.W. in spaceGravitational Wave (G.W.)direct prediction of general relativity

Low frequency G.W. sources (0.1mHz-1Hz):• Binary of super mass black holes• Extreme mass ratio in-spirals• Intermediate mass ratio in-spirals• Binary of compact objects • ……

Go to space to avoid seismic noise

Pioneer mission LISA (eLISA)LISA type missions• BBO• DECIGO• ALIA• Chinese proposal (10mHz-1Hz)

110 pm

Detecting G.W. in space----A bite of China

2008

2011

2012

2014

Independent proposal

[1] Gong, Xuefei, et al. "A scientific case study of an advanced LISA mission."Classical and Quantum Gravity 28.9 (2011): 094012.

IMRIs and binary of B.H.s formed by Pop III stars[1]

collaboration of space laser interferometer G.W. detection between CAS and ESA

Technology demonstration mission proposed, building prototypes

Official Chinese space G.W. detection working group constituted

LISA X symposium

IMECH assigned to build SLI

Institutes of CAS, Universities, satellite companies

Recent progress in China

Introduction to SLI----constitution

S.C.1 S.C.2

Million Kilometers

Heterodyne detection & non-Gaussian profile weak light phase lock

20MHz, 10pw, top-hat beam profile, locking precision

Introduction to SLI----constitution

Hardware:• Laser, pre-stabilized to ;• Interferometer, , ;• Telescope, , ;• Phase meter, ;• Pointing ahead angle mechanism.

Introduction to SLI----key technologies

Shot noise

Laser frequency noise

Clock jitter noise

Pointing jitter noise

Big telescope, high laser power [1]

Pre-stabilization, arm-locking, TDI [2]

Sideband-sideband scheme [3]

Pointing control techniques [1]

[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.

Data pre-processing and etc.

Clock sync., ranging & laser comm. [1, 4]

[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• Stable laser source• Ultra stable interferometer• Ultra stable telescope• High precision phase meter• Pointing ahead angle mechanism

Key technique

• Arm-locking• TDI• USO noise cancellation scheme• Pointing control techniques• Clock synchronization• Laser ranging• Interferometeric laser communication

SLI development in IMECH---- A brief introduction

2010

2012

2014

Funded by national space science center

Methodological demonstration: homodyne V.S. heterodyne [1]

Funded by Chinese Academy of Science

building hardware, prototype testing, technology development

LISA X symposium 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

Polarizing interferometerRectangular and straightforward Fewer componentEqual arm-length

Noisy laser source: worse than 1MHz/√HzAchieve 100pm/√Hz, thermal noise dominates

SLI development in IMECH---- the phase meter

Based on FPGADPLL4 channelsSignal frequency 1-2MHzOutput frequency >200Hz

LISA Symposium X, section Interferometry and Optics, Thursday, May 22nd, 17:15-17:30

SLI development in IMECH---- the pointing control

Pointing control demonstration

Differential Wave Sensing [1]

[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

Slave laser

Interferometer Phase meterPhase

difference

Gaussian profile1mW powerLocking precision mrad

Interferometer noise dominates

Summary & outlooks

Methodology • Heterodyne detection• Top-hat beam profile weak light phase lock

• A• N

Hardware• Stable laser source• Ultra stable interferometer• Ultra stable telescope• High precision phase meter• Pointing ahead angle mechanism

• N• A• N• A• N

Key technologies

• Arm-locking• TDI• USO noise cancellation scheme• Pointing control techniques• Clock synchronization• Laser ranging• Interfermeteric laser communication

• N• N• N• A• N• N• N

• 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.

Acknowledgement

Thank you all