A digitized atomic clock based on transient oscillation of detuned coherent population trapping

We demonstrated a digitized atomic clock which is based on the transient oscillation of detuned coherent population trapping (DCPT). In the Λ structure atomic states system, the DCPT oscillation frequency exactly equals the absolute value of the frequency difference between the two pump laser fields minus the two ground states hyperfine splitting frequency. This DCPT atomic clock obtains the standard frequency by adding/subtracting the DCPT frequency from the laser modulation RF frequency. And it does not require a phase locking loop circuit to lock the standard frequency to the atomic transition. In addition, its data processing section can be easily digitized with high accuracy. The frequency instability of 1×10^-11/τ^1/2 (τ=1000s) has been achieved.