0000000000328691

AUTHOR

E. A. Yakshina

Simple digital system for tuning and long-term frequency stabilization of a CW Ti:Sapphire laser

We have implemented a simple digital system for long-term frequency stabilization and locking to an arbitrary wavelength of the single-frequency ring CW Ti:Sapphire laser. This system is built using two confocal Fabry-Perot cavities, one of which is used to narrow the short-term linewidth of the laser and the other to improve the long-term stability of the laser frequency. The length of the second cavity is stabilized using the radiation from an external-cavity diode laser locked to an atomic transition. Our system is an improvement of a commercial Tekhnoscan laser lock. This system has been successfully used in our experiments on high-resolution laser spectroscopy of ultracold rubidium Ryd…

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Controlling the interactions of a few cold Rb Rydberg atoms by radiofrequency-assisted F\"orster resonances

Long-range interactions between cold Rydberg atoms, which are used in many important applications, can be enhanced using F\"orster resonances between collective many-body states controlled by an external electric field. Here we report on the first experimental observation of highly-resolved radio-frequency-assisted F\"orster resonances in a few cold Rb Rydberg atoms. We also observed radio-frequency-induced F\"orster resonances which cannot be tuned by a dc electric field. They imply an efficient transition from van der Waals to resonant dipole-dipole interaction due to Floquet sidebands of Rydberg levels appearing in the rf-field. This method can be applied to enhance the interactions of a…

research product

A simple digital system for tuning and long-term frequency stabilisation of a CW Ti:Sapphire laser

We have implemented a simple and cost-effective digital system for long-term frequency stabilisation and locking to an arbitrary wavelength of the single-frequency ring CW Ti:Sapphire laser. This system is built around two confocal Fabry-Perot cavities, one of which is used to narrow short-term line width of the laser and the other to improve long-term stability of the laser frequency. The second interferometer is also in the path of the radiation from an external-cavity diode laser stabilized to an atomic transition. Our system is an extension of a commercial Tekhnoscan laser lock. This system has been successfully used in experiments on high-resolution laser spectroscopy of ultracold Rydb…

research product

Controlling the interactions of a few cold Rb Rydberg atoms by radiofrequency-assisted F��rster resonances

Long-range interactions between cold Rydberg atoms, which are used in many important applications, can be enhanced using F��rster resonances between collective many-body states controlled by an external electric field. Here we report on the first experimental observation of highly-resolved radio-frequency-assisted F��rster resonances in a few cold Rb Rydberg atoms. We also observed radio-frequency-induced F��rster resonances which cannot be tuned by a dc electric field. They imply an efficient transition from van der Waals to resonant dipole-dipole interaction due to Floquet sidebands of Rydberg levels appearing in the rf-field. This method can be applied to enhance the interactions of almo…

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Line shapes and time dynamics of the F��rster resonances between two Rydberg atoms in a time-varying electric field

The observation of the Stark-tuned F\"orster resonances between Rydberg atoms excited by narrowband cw laser radiation requires usage of a Stark-switching technique in order to excite the atoms first in a fixed electric field and then to induce the interactions in a varied electric field, which is scanned across the F\"orster resonance. In our experiments with a few cold Rb Rydberg atoms we have found that the transients at the edges of the electric pulses strongly affect the line shapes of the F\"orster resonances, since the population transfer at the resonances occurs on a time scale of $\sim$100 ns, which is comparable with the duration of the transients. For example, a short-term ringin…

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