A Reflection-Type Vapor Cell for Micro Atomic Clock
This paper reports the design, fabrication and evaluation of a reflection-type Rb vapor cell with a Glass/Si/Glass structure for chip-scale micro atomic clocks. To miniaturize the cell and obtain a Rb resonance signal with a high sensitivity, long laser light traveling pass on the horizontal plane is required in the vapor cell. The horizontal Rb vapor cell with integrated mirrors are proposed and developed. A (100)-oriented Si wafer with cut off 9.74° toward [011] direction was used to make 45° mirrors by using anisotropic wet etching. Also, 90° mirrors were fabricated by Si deep RIE (Reactive Ion Etching) and H2 annealing. Absorption line of Rb was confirmed and CPT (Coherent Population Trapping) resonance was demonstrated in the fabricated devices.
