Microfabrication of 85Rb Vapor Cell for Chip-Scale Atomic Clocks

We describe the fabrication of Rubidium (Rb) vapor cells using glass-silicon anodic bonding techniques and chemical reaction between rubidium chloride and barium azide. The pore metallic Rb drops and buffer gases were obtained in the cells with few mm(3) internal volumes. The optical absorption resonance of Rb-85 D1 transition with proper broadening and the corresponding coherent population trapping (CPT) resonance, with a signal contrast of 1.5% and linewidth of about 1.7 KHz, have been detected at 90 degrees C.