Microfabricated atomic clocks based on coherent population trapping
This work was focussed on the development and improvement in the technology of miniature atomic clocks. The aim was to combine the microelectromechanical systems (MEMS) technology with advanced atomic interrogation techniques to produce high performance atomic clocks that are suitable for many new applications such as in hand held GPS receivers and cellular phones. The use of MEMS techniques allowed over a hundred fold reduction in size and power requirements of miniature atomic clocks. This combined with MEMS mass production capabilities has opened up whole new avenues for applying atomic clock technology.
During the course of this thesis work, we demonstrated the first prototype physics package of a microfabricated atomic clock. The physics package had typical fractional frequency instability of 4 × 10-11 at 1 s, had a volume of 12 mm3, and consumed less than 75 mW of power. Several new and innovative schemes were then proposed and developed to further improve the performance of microfabricated atomic clocks. These techniques focused on increasing the strength of the atomic resonance, increasing the contrast of the atomic resonance, reducing the noise accompanying the atomic resonance and reducing light-shift-induced frequency drifts in atomic clocks. At this stage, a majority of the ground work has been done for implementation of these advanced techniques in a miniature physics package.