Measurement protocol for large dynamic range and high sensitivity of an evanescent-field-mode guided atom interferometer

DWPI Title: Method for measuring acceleration of light-pulse atom interferometer (LPAI) accelerometer structure, involves determining optimal interrogation time to effect revival of Raman coherence in measurement of loaded laser cooled atoms, and undertaking LPAI optical sequence
Abstract: A large-dynamic and high-sensitive measurement protocol of an evanescent-field-mode guided atom interferometer accelerometer is disclosed. Cold atoms of a finite temperature are one-dimensionally guided in an evanescent field optical dipole trap. The first-step pathfinder protocol employs the revival of atomic coherence, i.e., the recovery of atomic fringe visibility to capture global interferometric signature to provide the information (e.g., a large-range of approximate acceleration sensing) to optimize the physical parameters for the second-step high-precision guided LPAI measurement. The contrast of atomic fringe visibility returns to unity given a specific interrogation time during the pulse sequence. To ensure the optimal interrogation time, the method employs a time-scanning sequence about the anticipated optimal interrogation time. The anticipated optimal interrogation time is determined via a conventional inertial measurement unit co-sensor or through the use of a look-up table. The method may alternatively employ a phase-scanning sequence.
Use: Method for measuring acceleration in a LPAI accelerometer structure such as 1-D EF-mode AI accelerometer.
Advantage: The method enables increasing the dynamic range of an LPAI in a high acceleration environment, i.e., the recovery of atomic fringe visibility, can be used as a pathfinder protocol to capture global interferometric signature to provide the information to optimize the physical parameters of high-precision LPAIs measurement. The method of high sensitivity acceleration measurements will aid in the realization of compact deployable cold atom inertial sensors. The 1-D EF-mode guided atom interferometer is significant for a deployable quantum gravity and inertial sensor due to it being compact, robust, energy efficient, and manufacturable, while exhibiting extended dynamic range. The EF ODT confines atoms in the transverse plane and allows the atoms to move freely along the direction of atom guiding, which can achieve strong atom-light interaction with reduced size,
Novelty: The method (600) involves providing a light-pulse atom interferometer (LPAI) accelerometer structure. A magneto-optical trap (MOT) about the suspended waveguide is formed (602). Atoms are laser cooled within a loading region about the suspended waveguide (604). An evanescent field optical dipole trap (EF ODT) is formed (606) about the suspended waveguide. The laser cooled atoms are loaded from a loading region into an evanescent field optical dipole trap (EF ODT) (608). An optimal interrogation time is determined (610) to effect revival of Raman coherence in a measurement of the loaded laser cooled atom. An LPAI optical sequence is undertaken and a population of states of the cooled atoms is measured (614) after the sequence. The MOT is formed by measuring the population to implement one of a time-scanning sequence or a phase- scanning sequence. An acceleration is determined (616) based upon the measured populations over one of the sequences.
Filed: 9/13/2023
Application Number: US18367604A
Tech ID: SD 15736.0
This invention was made with Government support under Contract No. DE-NA0003525 awarded by the United States Department of Energy/National Nuclear Security Administration. The Government has certain rights in the invention.
Data from Derwent World Patents Index, provided by Clarivate
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