摘要:
A method of fabricating compact alkali vapor filled cells that have volumes of 1 cm3 or less that are useful in atomic frequency reference devices such as atomic clocks. According to one embodiment the alkali vapor filled cells are formed by sealing the ends of small hollow glass fibers. According to another embodiment the alkali vapor filled cells are formed by anodic bonding of glass plates to silicon wafers to seal the openings of holes formed in the silicon wafers. The anodic bonding method of fabricating the alkali vapor filled cells enables the production of semi-monolithic integrated physics packages of various designs.
摘要:
A method is provided for optimizing the performance of laser-pumped atomic frequency references with respect to the laser detuning and other operating parameters. This method is based on the new understanding that the frequency references short-term instability is minimized when (a) the laser frequency is tuned nominally a few tens of MHz away from the center of the atomic absorption line, and (b) the external oscillator lock modulation frequency is set either far below or far above the inverse of the optical pumping time of the atoms.
摘要:
A microwave frequency standard is provided which allows for miniaturization down to length scales of order one micron, comprising a modulated light field originating from a laser that illuminates a collection of quantum absorbers contained in a micro-machined cell. The frequency standard of the present invention can be based on all-optical excitation techniques such as coherent population trapping (CPT) and stimulated Raman scattering or on conventional microwave-excited designs. In a CPT-based embodiment, a photodetector detects a change in transmitted power through the cell and that is used to stabilize an external oscillator to correspond to the absorber's transition frequency by locking the laser modulation frequency to the transition frequency. In a stimulated Raman scattering (SRS) embodiment, a high-speed photodetector detects a laser field transmitted through the cell beating with a second field originating in the cell. Both the locked laser modulation frequency and the beat frequency are very stable as they are referenced directly to the atomic transition.
摘要:
A method and apparatus are disclosed for precisely stabilizing a laser to a sub-Doppler resonance of an absorbing gas contained in a cell located external to the laser resonator. Stabilization is based on the detection of modulation transferred onto a previously unmodulated probe beam by the non-linear interactions of the absorbing gas located in a cell which is subject to a counter-running, frequency-modulated saturation beam. Alternatively, the further modulation of the saturation beam can be detected.
摘要:
An atomic slower comprises a bore and one or more tapered permanent magnets configured to produce an axial magnetic field along an axis of the bore.