Ne w tr anspor ta b le a tom sensor s and their a pplica tions to...
Transcript of Ne w tr anspor ta b le a tom sensor s and their a pplica tions to...
P. Bouyer
Source Atomiques Cohérentes et Interférométrie Atomique
Groupe d’Optique AtomiqueLaboratoire Charles Fabry de l’Institut d’Optique
Campus Polytechnique, France
New transportable atom sensors and their applications to space experiments
Atom Interferomtry : basic principle
Atom Inertial Base (gyro + accelerometer)
Coherent Atom Sensors
The next 0-g Campaign
I.C.E. : Tranportable Sensor with atom laser
September 06 Transportable Atom Sensors ... - P. BOUYER 3
Atom accelerometer
! Based on Raman pulses atom optics" !/2 " ! " !/2 (Kasevich & Chu 1991) : interferometer
"!/2 : create a superposition of 2 different velocities : beam splitter
"! : exchanges velocities : mirror
! We use an (optical) ruler to precisely measure the (atomic) test mass position
" Similar to falling corner cube gravimeter (FG5)"FG 5 : Laser phase is read by optical interferometry
"Atom sensor : Laser phase is read by atom interferometry.
! An Atom Interferometer “reads” the position of an atom proof mass using some kind of “laser telemetry”
"Velocity measurement improves with time
"Acceleration measurement improves with time"Absolute accuracy
"Example : watt balance for kg definition
"Performances Similar to best sensors"Extension to low frequency
September 06 Transportable Atom Sensors ... - P. BOUYER 4
Atom Gyrometer
! 3 Raman pulses separated in time
" Atoms with an initizal velcity perpendicular to lasers
"sensitivity to rotation = coriolis acceleration
Atom Interferomtry : basic principle
Atom Inertial Base (gyro + accelerometer)
Coherent Atom Sensors
The next 0-g Campaign
I.C.E. : Tranportable Sensor with atom laser
September 06 Transportable Atom Sensors ... - P. BOUYER 6
ControlReal-time
Fibre optics
Typical Atom Sensor Architecture
Light Source
MeasurementCamera,
accelerometer
Atomic Physics Chamber
Robust, flexible
ComputingMan-machine
interface
September 06 Transportable Atom Sensors ... - P. BOUYER 7
Maximum interaction time : 80 ms 3 rotation axes, 2 acceleration axesCycling frequency 2HzSensitivity (106 at):
• gyroscope : 3,5 10-7 rad.s-1.Hz-1/2
• accelerometer : 8 10-7 m.s-2.Hz-1/2
50 c
m
30 cmOne pair of Raman lasers switched on 3 times
Magneto-Optical Traps
Detections
Launching velocity: 2.4 m.s-1
Horizontal velocity: 0.33 m.s-1
Cold Atom Inertial Base (SYRTE)
SEE FOLLOWING TALK ON GRAVIMETER
September 06 Transportable Atom Sensors ... - P. BOUYER 8
Metrology" Accelerometer precision of a few 10-10 m/s2 per shot (5 s interrogation time)" Limit due to Raman-laser phase noise
" Noise comes from quartz oscillator
It is possible to go to a few seconds of interrogation time" Well suited for space applications" Best atom source ?
Nyman et al., cond-mat/0605057 and App. Phys. B 84(4) 673
Ultimate limits for atom accelerometers ?
Atom Interferomtry : basic principle
Atom Inertial Base (gyro + accelerometer)
Coherent Atom Sensors
The next 0-g Campaign
I.C.E. : Tranportable Sensor with atom laser
September 06 Transportable Atom Sensors ... - P. BOUYER 10
Why Coherent Source
0.01
0.1
1
10
100
1000
Tem
péra
ture
maxim
ale
(µK
)
0.012 3 4 5 6 7
0.12 3 4 5 6 7
12 3 4 5 6 7
10
Temps d'interrogation (s)
BEC
Sub Doppler
! Ultra cold! Longer interrogation
! Better signal to noise
! but lower flux !
! Atom Laser : space applications
! Small source
! «New» Physics
! Correlation, condensed matter
Le Coq et al., App. Phys. B 84(4)
September 06 Transportable Atom Sensors ... - P. BOUYER
Gravitational “resonator” for BEC
11
2 resonance conditionBragg (or Raman) resonanceOscillation resonance
Impens, Bouyer, Bordé , App. Phys. B 84(4)
September 06 Transportable Atom Sensors ... - P. BOUYER 12
!Heisenberg limited with
number states!Compensates low atom number S/N=106
!Integrated interferometers"BEC on chips
!«active» interferometers"Matter wave amplification»
BEC : New generation of Interferometers
September 06 Transportable Atom Sensors ... - P. BOUYER 13
A Guided Atom Laser
!BEC in hybrid (magnetic+optical) trap"Focused Nd:YAG laser (red detuned: 1064 nm)
"Anisotrop: 2,5 Hz ! 360 Hz ( zR= 2.7 mm )
"Waist position chosen with translational stage
"It is possible to use RF outcouplig"RF extracted matter wave is guided in the optical trap"Large de Broglie wavelength (1 µm)
! So far, RF outcoupled lasers from a magnetic trap" Once atom lasers are extracted, they are subjected to gravity" ! becomes quickly very small
W. Guerin et al., cond-mat/0607438
Atom Interferomtry : basic principle
Atom Inertial Base (gyro + accelerometer)
Coherent Atom Sensors
The next 0-g Campaign
I.C.E. : Tranportable Sensor with atom laser
September 06 Transportable Atom Sensors ... - P. BOUYER 15
September 06 Transportable Atom Sensors ... - P. BOUYER 16
ICE : Strategy
!Use optical traps for “atom cavity” !Optical fields easilly switchable
" No stray fields, only “diffusive effects”" Precision knowledge on position, velocity …
Compact BEC source : " Crutial : e!cient loading scheme into the optical trap" Need powerfull laser
September 06 Transportable Atom Sensors ... - P. BOUYER 17
Box superstructure Damped (foam filled) Grooves for adding optics
anywhere in the volume Breadboard (low vibration)
Suspend vacuum chamber with ropes, slings, chains
Adjust tension with turnbuckles
I. C. E. :Cube
87Rb MOT, 10/02/200
6
2!108 at. in <5s
September 06 Transportable Atom Sensors ... - P. BOUYER 18
I. C. E. : Cubes (with atoms)
87Rb MOT, 10/02/200
6
2!108 at. in <5s
Box superstructure Damped (foam filled) Grooves for adding optics
anywhere in the volume Breadboard (low vibration)
Suspend vacuum chamber with ropes, slings, chains
Adjust tension with turnbuckles
September 06 Transportable Atom Sensors ... - P. BOUYER
Optical Trapping with telecom lasers
19
Using High power telecom laser to trap and manipulate the atoms.
First trapping signal observed
Transportability tested during lab moving
Atom Interferomtry : basic principle
Atom Inertial Base (gyro + accelerometer)
Coherent Atom Sensors
I.C.E. : Tranportable Sensor with atom laser
The next 0-g Campaign
September 06 Transportable Atom Sensors ... - P. BOUYER 21
Env. 10 mg max = 1s interrogation
Performances : 10-10 m.s-2 .Hz-1/2
100 measures # 10-11 m.s-2
Need special isolation platform
I.C.E. : 0-g tests
September 06 Transportable Atom Sensors ... - P. BOUYER
I.C.E. : 0-g tests
22
“Benchtest” experiment for testing atom manipulation with laser technology.
“flight” ready for March 26th.
No Coherent Atoms yet
Atom Interferomtry : basic principle
Atom Inertial Base (gyro + accelerometer)
Coherent Atom Sensors
I.C.E. : Tranportable Sensor with atom laser
The next 0-g Campaign
P. Bouyer
Source Atomiques Cohérentes et Interférométrie Atomique
Groupe d’Optique AtomiqueLaboratoire Charles Fabry de l’Institut d’Optique
Campus Polytechnique, France
Philippe BOUYERRobert NYMANGaël VAROQUAUXJean-François CLEMENTJean-Philippe BRANTUTFrancois Impens Arnaud LANDRAGINFrank PEREIRAChristian BORDE Alexandre BRESSONYannick BIDELFrançois DEYSACPierre TOUBOUL
Linda MONDINMichel ROUZEJean MIGNOT
http://www. IFRAF.org/ http://www.atomoptic.fr/http://www.ice-space.fr/
Post-doctoral position available. See www.atomoptic.fr
Thomas BourdelMartin St-Vincent
Nassim ZahzamOlivier Carraz