Research On Miniaturization Of Atomic Clock Based On Coherence Population Trapping

As precise timekeeper, atomic clock can play an important role in defferent fields such as astonomy, aerospace, navigation and physics. But it is not used widely until now for its big volume. The miniaturization of atomic clock will helpful to enlarge the application fields of atomic clock, and then will bring deep influence on the world in both society and economy. So the miniature atomic clock is becoming the research direction of atomic clock in recent years. In this dissertation the author has studied the principle, design and manufacture about miniature atomic clock.The control model of atomic clock is deduced on the base of coherence population trapping (CPT). Control model base on physical principle would be much useful in the realization of atomic clock, but be difficult in modeling of physical package. Base on the resonance equation of CPT, the equivalent equation as a function of modulating frequency is deduced from the modulation process. The method for locking frequency according to CPT line is studied. The model of frequency detection for physical package is attained according to analysis the course of detection. Then base on the construction of atomic clock the frequency control model is obtained and then different design methods are studied. The methods for studying long term stability and short term stability of atomic clock on the base of control model are studied simultaneously.The concept of chip-scale atomic clock is introduced, the common foundations of miniature atomic clock such as material, manufacture and package are discussed. The technologies for realization of miniature physical package are studied. Base on MEMS technologies some relevant practical works for miniature physical package are performed.Anodic bonding, the MEMS technology for realization of alkali vapor cell with a structure of glass-silicon-glass is studied deeply. The source of current during anodic bonding is explained and the theoretical model for forecasting bonding result is presented. According to the electric character of glass, the character during anodic bonding is studied and the model for analyzing and comparison of currents under different conditions such as temperature and applied voltage is obtained. The physical model for anodic bonding is constructed base on valence bond theory, and the essence relationship between bond result and circuit character is obtained. Base on the above two results, analytical model for bond result under different conditions is obtained. The bonding course of innovation operation of anodic bonding, multi-stick anodic bonding using two electrodes is studied on the base of valence bond theory, the reason for current spike during bonding is given. Relevant experimental studies are performed.Some relevant problems in the course of experiment are discussed. Prototype of miniature atomic clock made by MEMS technology is introduced chiefly.