MICRO VAPOR CELLS SEALED BY TWO-STEP BONDING FOR MINIATURE ATOMIC CLOCKS

This study introduces a new method to fabricate and evaluation of vapor cells with Rb sealed by anodic bonding at wafer level for miniature atomic clocks. The proposed method achieves miniaturization and long-term frequency stability by the wafer-level process. Rb encapsulation is achieved by two-step bonding. The vapor cells are fabricated to seal with buffer gas to confirm the stability, and the achieved Allan deviation at an averaging time of 3000 s is 1.7 x 10(-11). These results show that the proposed method has improved the long-term stability and has achieved miniaturization compared to the vapor cell fabricated by the conventional method, which uses an alkali-atom dispenser.