Fiber Optics with Laser Cooled atoms

Maxim Olshanii, Yu. B. Ovchinnikov, Vladilen S Letokhov

Lin Li, Cuiyun Zhou, Wei Xiong +16 more

In the development of the Cold Atom Physics Research Rack (CAPR) on board the Chinese Space Station, the laser system plays a critical role in preparing the all-optical 87Rb Bose–Einstein condensates (BECs). An all-fiber laser system has been developed for CAPR to provide the required optical fields for atom interaction and to maintain the beam pointing in long-term operation. The laser system integrates a 780 nm fiber laser system and an all-fiber optical control module for sub-Doppler cooling, as well as an all-fiber 1064 nm laser system for evaporative cooling. The high-power, single-frequency 780 nm lasers are achieved through rare-Earth doped fiber amplification, fiber frequency-doubling, and frequency stabilization technology. The all-fiber optical control module divides the output of the 780 nm laser system into 15 channels and regulates them for cooling, trapping, and probing atoms. Moreover, the power consistency of each pair of cooling beams is ensured by three power tracking modules, which is a prerequisite for maintaining stable MOT and molasses. A high-power, compact, controlled-flexible, and highly stable l064 nm all-fiber laser system employing two-stage ytterbium-doped fiber amplifier (YDFA) technology has been designed for evaporative cooling in the optical dipole trap (ODT). Finally, an all-optical 87Rb BEC is realized with this all-fiber laser system, which provides an alternative solution for trapping and manipulating ultra-cold atoms in challenging environmental conditions.

Michael J. Renn, Don Montgomery, O. Vdovin +3 more

Pedro Antonio Quinto-Su, M. Tscherneck, M. Holmes +1 more

We have used an optical fiber based system to implement optical detection of atoms trapped on a reflective "atom-chip". A fiber pair forms an emitter-detector setup that is bonded to the atom-chip surface to optically detect and probe laser cooled atoms trapped in a surface magneto-optical trap. We demonstrate the utility of this scheme by measuring the linewidth of the Cs D2 line at different laser intensities.

王秀梅 Wang Xiumei, Danyang Wang, Yifei Wang +8 more

SummaryDiffuse laser cooling provides a compact cold atom system for quantum precision measurement processes, especially for the integrating sphere cold atom clock. However, the laser cooling system of current integrating sphere cold atom clock is bulky and complex, which is not conductive to the miniaturization of cold atom clock. In order to make a less complex diffuse laser cooling system, we adopt the scheme to combine the fiber mirrors and the diffuse laser cooling technique. The incident laser beams are reflected by the fiber mirrors and teflon, and the atoms can be successfully cooled and detected in the miniaturized zone. The preparation of fiber mirrors and the realization of diffuse laser cooling system with a simple optical system can lay a solid foundation for further miniaturization of the overall system of integrating sphere cold atom clock in the future.

Jörg Helge Müller, D. Bettermann, V. Rieger +10 more