Method and system for operating an atomic clock with simultaneous locking of field and frequency
US6888780B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 12, 2004 |
| Grant date | May 3, 2005 |
| Priority date | — |
| Expiry date | Mar 22, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG04F5/14
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention provides a method and system to simultaneously use the microwave and Zeeman end resonances associated with the same sublevel of maximum (or minimum) azimuthal quantum number m to lock both the atomic clock frequency and the magnetic field to definite values. This eliminates the concern about the field dependence of the end-resonance frequency. In an embodiment of the system of the present invention, alkali metal vapor is pumped with circularly-polarized D1 laser light that is intensity-modulated at appropriate resonance frequencies, thereby providing coherent population trapping (CPT) resonances. In another embodiment, pumping with constant-intensity circularly-polarized D1 laser light enhances magnetic resonances that are excited by alternating magnetic fields oscillating at appropriate resonance frequencies. In both embodiments, the resonances are greatly enhanced by concentrating most of the atoms in the initial state of the resonances, and by diminishing the spin-exchange broadening of the resonances. This leads to greater stability of optically pumped atomic clocks. This invention can also be used to operate an atomic magnetometer, where the feedback sign…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.