OPTICALLY PUMPED FREQUENCY STANDARD WITH REDUCED AC STARK SHIFT

摘要

PROBLEM TO BE SOLVED: To provide an optically pumped frequency standard which can be realized at low cost. SOLUTION: An apparatus (20) for generating a stabilized frequency signal is disclosed. The apparatus (20) includes a quantum absorber (13) having first, second, and third energy states. The quantum absorber (13) is irradiated by a first radiation source (21) that generates electromagnetic radiation having a frequencyνLthat induces transitions between the first and third energy states. The quantum absorber (13) is also irradiated by a second radiation source (18) that generates electromagnetic radiation having a frequencyνMthat induces transitions between the first and second energy states. A detector that generates a detector signal indicative of the level of radiation leaving the quantum absorber (13) in a frequency range includingνLis used by a number of servo loops. One of the servo loops determines the value ofνLthat minimizes or maximizes the detector signal and one other servo loop (31) determines an offset signal that reduces the dependence ofνMon the intensity of the first radiation source (21). COPYRIGHT: (C)2006,JPO&NCIPI