Biomedical subjects

V Gerginov

Publications and source records attributed to V Gerginov.

4 recordsLinked to original sources

PubMed2006

Compact phase delay technique for increasing the amplitude of coherent population trapping resonances in open Lambda systems.

We propose and demonstrate a novel technique for increasing the amplitude of coherent population trapping (CPT) resonances in open Lambda systems. The technique requires no complex modifications to the conventional CPT setup and is compatible with standard microfabrication processes. The improvement in the CPT resonance amplitude as a function of intensity of the excitation light agrees well with the theory based on ideal open and closed Lambda systems.

Journal Article↗

PubMed2006

Atomic-based stabilization for laser-pumped atomic clocks.

We describe a novel technique for stabilizing frequency shifts in laser-interrogated vapor-cell atomic clocks. The method suppresses frequency shifts due to changes in the laser frequency, intensity, and modulation index as well as atomic vapor density. The clock operating parameters are monitored by using the atoms themselves, rather than by using conventional schemes for laser frequency and cell temperature control. The experiment is realized using a chip-scale atomic clock. The novel atomic-based stabilization approach results in a simpler setup and improved long-term performance.

Journal Article↗

PubMed2005

Atomic vapor cells for chip-scale atomic clocks with improved long-term frequency stability.

A novel technique for microfabricating alkali atom vapor cells is described in which alkali atoms are evaporated into a micromachined cell cavity through a glass nozzle. A cell of interior volume 1 mm3, containing 87Rb and a buffer gas, was made in this way and integrated into an atomic clock based on coherent population trapping. A fractional frequency instability of 6 x 10(-12) at 1000 s of integration was measured. The long-term drift of the F=1, mF=0-->F=2, mF=0 hyperfine frequency of atoms in these cells is below 5 x 10(-11)/day.

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PubMed2005

High-resolution spectroscopy with a femtosecond laser frequency comb.

The output of a mode-locked femtosecond laser is used for precision single-photon spectroscopy of 133Cs in an atomic beam. By changing the laser's repetition rate, the cesium D1 (6s 2S(1/2)-->6p 2P(1/2)) and D2 (6s 2S(1/2)-->6p 2P(3/2)) transitions are detected and the optical frequencies are measured with accuracy similar to that obtained with a cw laser. Control of the femtosecond laser repetition rate by use of the atomic fluorescence is also implemented, thus realizing a simple cesium optical clock.

Journal Article↗