Atom-based stabilization for laser-pumped atomic clocks

Progress towards simplification and improvement of the long-term stability of chip-scale atomic clocks is presented. The conventional technique of laser optical frequency and cell temperature control is compared with a novel technique which avoids the use of temperature sensors. The technique results in a simpler setup and improved long-term performance. Here, laser frequency, laser intensity, RF modulation index and vapor cell atomic density are stabilized using exclusively information from the atoms in the vapor cell. Different feedback schemes for laser intensity and frequency stabilization, as well as cell temperature control are experimentally compared. Their relevance to future design of chip-scale devices is discussed.