Cesium based laser-atomic oscillator

We report the first demonstration of a laser-atomic oscillator with cesium (Cs) atoms. A laser-atomic oscillator is analogous to an active mode-locked laser with a self-excited modulator, i.e., atoms, at a ground-state hyperfine transition frequency. Therefore, a laser-atomic oscillator can be configured as the simplest active atomic clock or a self-oscillating, earth-field atomic magnetometer that delivers oscillation signals both optically and electrically. With the current experimental Cs laser-atomic oscillator (Cs-LAO) setup, when it is configured as an atomic clock using the 0–0 hyperfine transition, the short-term fractional frequency instability is around the 10−10 level. When it is configured as a self-oscillating magnetometer using a magnetically sensitive 3–3 hyperfine transition, the magnetic field sensitivity is around 100 fT/Hz at 60 Hz. The presented Cs-LAO uses a cavity length from ∼6.5 to ∼11.4 cm. Ultimately, the minimal length of a Cs-LAO device can be ≤1.63 cm. Our new efforts unlock the potential of building truly chip-scale atomic clocks and magnetometers.