A Dielectric Metasurface Optical Chip for the Generation of Cold Atoms

Compact and robust cold atom sources are increasingly important for quantum research, especially for transferring cutting-edge quantum science into practical applications. In this letter, we report on a novel scheme that utilizes a metasurface optical chip to replace the conventional bulky optical elements used to produce a cold atomic ensemble with a single incident laser beam, which is split by the metasurface into multiple beams of the desired polarization states. Atom numbers $~10^7$ and temperatures (about 35 ${\mu}$K) of relevance to quantum sensing are achieved in a compact and robust fashion. Our work highlights the substantial progress towards fully integrated cold atom quantum devices by exploiting metasurface optical chips, which may have great potential in quantum sensing, quantum computing and other areas

New Polyphase Complementary Sequence Sets for Wireless Communication Systems

In contemporary wireless communication systems, complementary sequences play fairly important roles. Based on polyphase perfect sequences (PPSs), this paper presents a construction method, whose basic idea is to sample a given PPS with equal space, for yielding a family of periodic polyphase complementary sequence sets (PPCSSs). The advantages of this method include the family size of resultant PPCSSs is the same as that of the PPSs employed, and the number and length of sub-sequences in the proposed PPCSSs can be altered on demand

Optical telescope with Cassegrain metasurfaces

The Cassegrain telescope, made of a concave primary mirror and a convex secondary mirror, is widely utilized for modern astronomical observation. However, the existence of curved mirrors inevitably results in bulky configurations. Here, we propose a new design of the miniaturized Cassegrain telescope by replacing the curved mirrors with planar reflective metasurfaces. The focusing and imaging properties of the Cassegrain metasurface telescopes are experimentally verified for circularly polarized incident light at near infrared wavelengths. The concept of the metasurface telescopes can be employed for applications in telescopes working at infrared, Terahertz, and microwave and even radio frequencies