(1)   Quantum Precision Measurement Based on Cold-Atom inside Hollow-Core Fibers

We investigate light-atom interactions within hollow-core optical fibers and aim to apply this technology to cold-atom inertial measurement instruments with ultra-high precision.

Due to their unique hollow-core structure, hollow-core fibers can simultaneously guide both light and atoms, making them an ideal platform for constructing quasi-one-dimensional, long-distance, and uniform atomic trapping potentials. By adiabatically loading cold atoms into a hollow-core fiber and constructing cold-atom interferometers using Raman or Bragg pulse sequences, ultra-high-precision measurements of gravitational acceleration and inertial acceleration can be achieved. Benefiting from the radial confinement provided by the hollow-core fiber, this type of interferometer theoretically exhibits strong adaptability to dynamic environments and enables vector gravitational measurements, showing great potential to significantly enhance the practical performance of existing cold-atom gravimeters.

Key experimental techniques involved in this research include: laser cooling of atoms, adiabatic atom loading, high-efficiency long-distance coherent guiding of cold atoms, in-fiber cooling and coherent manipulation of atoms, and fiber-based atom detection technologies.

(2)   Ultra-High Sensitivity Electric Field Sensing Based on Rydberg atoms in Fiber Microcavities

This research focuses on the development of a highly compact and sensitive electric field sensing platform by integrating Rydberg atom-based electromagnetically induced transparency (EIT) with fiber-based micro-optical cavities. The system exploits the exceptional electric field responsiveness of Rydberg atoms and the strong spatial confinement of light and atoms in a fiber microcavity, enabling ultra-high-sensitivity, non-perturbative measurement of microwave electric fields. Its miniaturized design allows for high-resolution electric field detection within highly constrained spaces, making it suitable for applications such as arrayed microwave radar and near-field electromagnetic field mapping.

Core technologies involved in this work comprise the design and fabrication of high-finesse fiber microcavities, Rydberg atom preparation and trapping, implementation of electromagnetically induced transparency (EIT) spectroscopy, and detection of microwave-electric-field-induced spectral shifts. Essential experimental skills include laser frequency stabilization, cavity quantum electrodynamics system control, microwave signal generation and modulation, and high-sensitivity optical heterodyne or homodyne detection techniques.