During the project, major efforts were devoted to the development and optimization of an all-fiber atom–nanofiber quantum optical platform based on cold atoms coupled to ultra-thin optical fibers.
A significant part of the work focused on improving the loading efficiency and collective interaction strength of atoms trapped around the nanofiber. To achieve this goal, the trapping configuration, cooling sequence, and optical alignment of the experimental system were systematically optimized. In particular, the orientation of the nanofiber was carefully adjusted in order to maximize the axial overlap between the trapped atomic ensemble and the nanofiber interaction region.
These developments resulted in a substantial enhancement of the optical depth of the system, increasing it from previously achieved values around 30 to values exceeding 200. This strong enhancement of atom–light interaction strength provides favorable conditions for studying collective quantum optical phenomena in waveguide-coupled atomic systems.
In parallel, first proof-of-principle optical storage experiments were successfully implemented within the upgraded platform. These experiments demonstrate the feasibility of realizing quantum optical storage functionalities in an all-fiber architecture compatible with future quantum network technologies.
The project also initiated investigations of nonlinear optical response and collective optical effects under weak optical probing conditions. Preliminary observations indicate the emergence of nonlinear behavior associated with strong collective atom–light interactions in the nanofiber-coupled system.
Overall, the project established a robust experimental platform for exploring collective quantum optics, waveguide-mediated interactions, and future fiber-integrated quantum photonic technologies.
