Diode-laser-pumped, gas-cell atomic clocks

Theoretical models indicate that laser optical pumping in rubidium gas cell atomic clocks afford the possibility of several orders of magnitude improvement in short-term performance over conventional lamp-pumped devices. Preliminary experiments indicating that the short-term stability is achievable are reported. Additionally, the spatial and temporal coherence of the laser affords possibilities for control of the long-term instability caused by light shift; that is, new geometries and cell types are possible because of the lasers´ spatial coherence while the temporal coherence and tunability allow one to operate at carefully chosen conditions to minimize light shift. All of this may allow total performance from a rubidium cell standard that rivals active hydrogen masers