An electro-optical simulator for eLISA
LOT : Lisa On Table
APC Laboratory, University Paris Diderot
P. Gruning, H. Halloin, J. Brossard, P. Prat, S. Baron, C. Buy ,P.
Jimenez
10th LISA Symposium, Gainesville Florida
May 20, 2014
Contents
1
LOT : Lisa On Table
The "optical" LOT
The "electronical" LOT
Current status of the experiment
APC Laboratory, University Paris Diderot P. Gruning,
An electro-optical
H. Halloin, simulator
J. Brossard,
for P.
eLISA
Prat, LOT
S. Baron,
: LisaC.
OnBuy
Table
,P. Jimenez
May10th
20, LISA
2014 Symposium,
2 / 17
Contents
1
LOT : Lisa On Table
The "optical" LOT
The "electronical" LOT
Current status of the experiment
2
Results
TDI : Time Delay Interferometry
Some plots
APC Laboratory, University Paris Diderot P. Gruning,
An electro-optical
H. Halloin, simulator
J. Brossard,
for P.
eLISA
Prat, LOT
S. Baron,
: LisaC.
OnBuy
Table
,P. Jimenez
May10th
20, LISA
2014 Symposium,
2 / 17
Contents
1
LOT : Lisa On Table
The "optical" LOT
The "electronical" LOT
Current status of the experiment
2
Results
TDI : Time Delay Interferometry
Some plots
3
Conclusion
APC Laboratory, University Paris Diderot P. Gruning,
An electro-optical
H. Halloin, simulator
J. Brossard,
for P.
eLISA
Prat, LOT
S. Baron,
: LisaC.
OnBuy
Table
,P. Jimenez
May10th
20, LISA
2014 Symposium,
2 / 17
Plan
1
LOT : Lisa On Table
The "optical" LOT
The "electronical" LOT
Current status of the experiment
2
Results
TDI : Time Delay Interferometry
Some plots
3
Conclusion
APC Laboratory, University Paris Diderot P. Gruning,
An electro-optical
H. Halloin, simulator
J. Brossard,
for P.
eLISA
Prat, LOT
S. Baron,
: LisaC.
OnBuy
Table
,P. Jimenez
May10th
20, LISA
2014 Symposium,
3 / 17
LOT : Lisa On Table, an electro-optical simulator of
eLISA
green : Command/Control
red : measurement
blue : LOT components
APC Laboratory, University Paris Diderot P. Gruning,
An electro-optical
H. Halloin, simulator
J. Brossard,
for P.
eLISA
Prat, LOT
S. Baron,
: LisaC.
OnBuy
Table
,P. Jimenez
May10th
20, LISA
2014 Symposium,
4 / 17
Optical part
2 blocks, each one simulating one satellite of eLISA
APC Laboratory, University Paris Diderot P. Gruning,
An electro-optical
H. Halloin, simulator
J. Brossard,
for P.
eLISA
Prat, LOT
S. Baron,
: LisaC.
OnBuy
Table
,P. Jimenez
May10th
20, LISA
2014 Symposium,
5 / 17
Optical part
a heterodyne Mach-Zehnder
interferometer
each arm = "cat’s eye"
configuration : association of
lens, polarizing plate, mirror
and acousto-optical
modulator
-> allows to generate the
optical beat signal + noise
without loosing alignement
between the distant and local
arms due to frequency shift
APC Laboratory, University Paris Diderot P. Gruning,
An electro-optical
H. Halloin, simulator
J. Brossard,
for P.
eLISA
Prat, LOT
S. Baron,
: LisaC.
OnBuy
Table
,P. Jimenez
May10th
20, LISA
2014 Symposium,
6 / 17
LOT : Lisa On Table, an electro-optical simulator of
eLISA, electronics part
NI PXIe
6537
GPS disciplined
oscillator
10 MHz
Synth.
x8
49.993
MHz
5 MHz max
Interface board
1 GHz
PD #1
Direct digital synthesizers
PD #2
Phasemeter
Channel #1
Channel #2
Channel #3
Channel #4
DDS #1
DDS #2
DDS #3
Ref
Signal
Ref
Signal
Ref
Signal
Ref
Signal
AOM #3
AOM #2
AOM #1
APC Laboratory, University Paris Diderot P. Gruning,
An electro-optical
H. Halloin, simulator
J. Brossard,
for P.
eLISA
Prat, LOT
S. Baron,
: LisaC.
OnBuy
Table
,P. Jimenez
May10th
20, LISA
2014 Symposium,
7 / 17
Improvement of the experiment
thermal insulation of the optical bench
use of air cushion
heat device to reduce turbulences by creating temperature layers
further improvements for the future :
piezo oscillators on the mirror for active correction of the optical
path lenght
transfer into a vacuum chamber
replacement of the NI device by a FPGA card
implementation of electro-optical modulators to simulate clock noise
corrections
coupling with LisaCode to simulate realistic variable delays and
frequency shifts due to orbitography and doppler effect
APC Laboratory, University Paris Diderot P. Gruning,
An electro-optical
H. Halloin, simulator
J. Brossard,
for P.
eLISA
Prat, LOT
S. Baron,
: LisaC.
OnBuy
Table
,P. Jimenez
May10th
20, LISA
2014 Symposium,
8 / 17
Active compensation of optical path
order 11 at flaser + 2x110MHz
+ noise
order 00 at flaser used for
homodyne interferometry
-> dark fringe to lock the
feedback system
local mirror oscillates at
30kHz to modulate laser
signal
distant mirror receives
correction signal from the
feedback system which uses
the 30kHz reference and the
photodiode output
APC Laboratory, University Paris Diderot P. Gruning,
An electro-optical
H. Halloin, simulator
J. Brossard,
for P.
eLISA
Prat, LOT
S. Baron,
: LisaC.
OnBuy
Table
,P. Jimenez
May10th
20, LISA
2014 Symposium,
9 / 17
Plan
1
LOT : Lisa On Table
The "optical" LOT
The "electronical" LOT
Current status of the experiment
2
Results
TDI : Time Delay Interferometry
Some plots
3
Conclusion
APC Laboratory, University Paris Diderot P. Gruning,
An electro-optical
H. Halloin, simulator
J. Brossard,
for P.
eLISA
Prat, LOT
S. Baron,
: LisaC.
OnBuy
Table
,P. Jimenez
May 10th
20, 2014
LISA Symposium,
10 / 17
TDI : Time Delay Interferometry
First generation TDI :
X1st = (1 − D310 D10 3 )sTT ;1 − (1 − D20 1 D10 2 )sTT ;10
a post-measurement treatment to reduce significantly the laser
frequency noise level
APC Laboratory, University Paris Diderot P. Gruning,
An electro-optical
H. Halloin, simulator
J. Brossard,
for P.
eLISA
Prat, LOT
S. Baron,
: LisaC.
OnBuy
Table
,P. Jimenez
May 10th
20, 2014
LISA Symposium,
11 / 17
First results
LTPDA 2.7 (R2013b)
2013−11−25 02:26:33.222 UTC
ltpda: f3f3872
iplot
2
10
LASD(freq chan 1)
LASD(freq chan 2)
LASD(freq chan 3)
LASD(freq chan 4)
LASD(TDI_f34)
0
ASD (Hz/sqrt(Hz))
10
−2
10
−4
10
−6
10
−2
10
−1
10
Frequency [Hz]
0
10
1
10
Illustration of TDI performance on triangular frequency fluctuations :
the main pic is nearly entirely suppressed
APC Laboratory, University Paris Diderot P. Gruning,
An electro-optical
H. Halloin, simulator
J. Brossard,
for P.
eLISA
Prat, LOT
S. Baron,
: LisaC.
OnBuy
Table
,P. Jimenez
May 10th
20, 2014
LISA Symposium,
12 / 17
TDI without local noise and equal length (noise
reference level)
108
eLISA phasemeter requirement
eLISA total interferometry requirement
so;1 (white freq. noise)
se;1 (white freq. noise)
X1st ;o
X1st ;o,Ref
X1st ;e
X1st ;e,Ref
106
√
Phase noise [cycle/ Hz]
104
102
÷ 5 × 107
100
10−2
÷ 400
10−4
10−6
10−8
10−4
10−3
10−2
10−1
100
101
Frequency [Hz]
Attenuation of 5.107 for optical LOT and 2.1010 for electronical LOT at
1mHz
APC Laboratory, University Paris Diderot P. Gruning,
An electro-optical
H. Halloin, simulator
J. Brossard,
for P.
eLISA
Prat, LOT
S. Baron,
: LisaC.
OnBuy
Table
,P. Jimenez
May 10th
20, 2014
LISA Symposium,
13 / 17
TDI with 3 arms noise and equal length
108
eLISA phasemeter requirement
eLISA total interferometry requirement
optical input freq noise
so;1 (delayed freq. noise)
se;1 (delayed freq. noise)
X1st ;o
X1st ;o,Ref
X1st ;e
X1st ;e,Ref
106
√
Phase noise [cycle/ Hz]
104
102
÷ 5 × 107
100
10−2
÷ 400
10−4
10−6
10−8
10−4
10−3
10−2
10−1
100
101
Frequency [Hz]
Same performance as for the configuration with no noise on local arm
APC Laboratory, University Paris Diderot P. Gruning,
An electro-optical
H. Halloin, simulator
J. Brossard,
for P.
eLISA
Prat, LOT
S. Baron,
: LisaC.
OnBuy
Table
,P. Jimenez
May 10th
20, 2014
LISA Symposium,
14 / 17
TDI with 3 arms noise and unequal length
108
eLISA phasemeter requirement
eLISA total interferometry requirement
optical input freq noise
so;1 (delayed freq. noise)
se;1 (delayed freq. noise)
X1st ;o
X1st ;o,Ref
X1st ;e
X1st ;e,Ref
106
√
Phase noise [cycle/ Hz]
104
102
÷ 5 × 107
100
10−2
÷ 20
10−4
÷ 20
10−6
10−8
10−4
10−3
10−2
10−1
100
101
Frequency [Hz]
Also a 5.107 attenuation for optical LOT but "only" 1.109 for electronical
LOT
-> interpolation order + jitter
APC Laboratory, University Paris Diderot P. Gruning,
An electro-optical
H. Halloin, simulator
J. Brossard,
for P.
eLISA
Prat, LOT
S. Baron,
: LisaC.
OnBuy
Table
,P. Jimenez
May 10th
20, 2014
LISA Symposium,
15 / 17
Plan
1
LOT : Lisa On Table
The "optical" LOT
The "electronical" LOT
Current status of the experiment
2
Results
TDI : Time Delay Interferometry
Some plots
3
Conclusion
APC Laboratory, University Paris Diderot P. Gruning,
An electro-optical
H. Halloin, simulator
J. Brossard,
for P.
eLISA
Prat, LOT
S. Baron,
: LisaC.
OnBuy
Table
,P. Jimenez
May 10th
20, 2014
LISA Symposium,
16 / 17
Conclusion
a complete hardware simulator of eLISA
application of first TDI generation on a hardware simulator
successfull
further improvements to reduce intrinsic noise are underway :
active compensation of optical path to get nearly the same
performance on optical and electronic LOT
implementation of FPGA to bypass NI system to have perfectly
synchronized output commands with reduced time jitter
Forthcoming developments :
Time variable delays and frequency shifts (TDI 2nd generation)
eLISA clock synchronization scheme with EOMs
arm-locking (thanks to FPGA)
improved electronics synchronized clocks with frequency reference
from a stabilized optical frequency combination
APC Laboratory, University Paris Diderot P. Gruning,
An electro-optical
H. Halloin, simulator
J. Brossard,
for P.
eLISA
Prat, LOT
S. Baron,
: LisaC.
OnBuy
Table
,P. Jimenez
May 10th
20, 2014
LISA Symposium,
17 / 17