Vibration Isolation Platform

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Table of contents

1 Introduction 
1.1 Cold atom inertial sensor
1.2 Sagnac based gyroscopes
1.3 Purpose of the thesis work
1.4 Plan of the Thesis
2 Basic concepts for cold atom interferometry 
2.1 Raman transition and light pulses
2.1.1 Principles
2.1.2 Stimulated Raman Transitions
2.2 Atom optics
2.3 Mach-Zehnder Atom interferometry – 3 pulse scheme
2.3.1 Phase shift for a constant acceleration
2.3.2 Phase shift for constant rotations – Sagnac effect
2.4 4-pulse Atom Gyroscope
2.4.1 Constant acceleration – Zero sensitivity
2.4.2 Rotation Sensitivity – Sagnac area
2.5 Sensitivity function of a 4 light pulse interferometer
2.5.1 Laser phase sensitivity
2.5.2 Acceleration phase noise
2.5.3 Rotation phase noise
2.6 Conclusion
3 Experimental Set-Up 
3.1 Lasers
3.1.1 Frequency chain
3.1.2 Cooling Laser system
3.1.3 Raman Laser system
3.2 Vacuum chamber – Atomic Fountain
3.2.1 2D MOT
3.2.2 3D MOT – Moving Molasses
3.2.3 Detection Region
3.2.4 Interferometric Region
3.2.5 Rabi oscillation
3.3 Vibration Isolation Platform
3.4 Rotation Stage
3.4.1 New Tilt Lock coil
3.5 Conclusion
4 Interleaved atom interferometry 
4.1 Continuous operation
4.1.1 Joint measurement
4.1.2 Interleaved Sequence
4.2 Methods
4.2.1 Acquisition and processing based on seismometers
4.2.2 Real-time Compensation of vibration noise
4.2.3 Mid Fringe Lock
4.3 Sensitivity of the Gyroscope
4.3.1 Sensitivity with interleaved scheme
4.3.2 Interpretation of vibration noise averaging in a joint scheme
4.4 Measurements of weak dynamic rotation rates
4.4.1 How to apply weak dynamic rotation rate
4.4.2 Classical sensor
4.4.3 AI sensor
4.5 Conclusion
5 Scale Factor and bias of the Gyroscope 
5.1 Gyroscope scale factor
5.1.1 Latitude estimation
5.1.2 Estimation of the initial bearing to north, N
5.1.3 Variation of interrogation time T
5.1.4 Proximity sensors
5.1.5 Estimation changing orientation by small angles d
5.1.6 Variation of the bearing to North using a rotation stage
5.2 Mirrors Alignment Bias
5.2.1 Interferometer contrast
5.2.2 Bias estimation
5.2.3 Mirrors alignment and Trajectory optimization
5.3 Conclusion
6 Non equal momentum transfer 
6.1 Parasitic Interferometer
6.2 DC acceleration sensitivity and ramp optimization
6.2.1 Frequency ramp
6.2.2 Ramp optimization
6.3 Non Equal keff momentum transfer
6.3.1 Change of exchanged momentum modulus
6.3.2 Zero sensitivity to DC acceleration
6.3.3 Probability noise and ramp optimization
6.3.4 Sensitivity to rotation – Scale factor
6.4 Conclusion
7 Conclusion 
A Estimation of visibility and amplitude noise 
B Publications 
Bibliography