PECULIARITIES OF RESONANT ABSORPTION AND FLUORESCENCE IN EXTREMELY THIN CELL FILLED WITH Rb AND BUFFER GAS.

Recently unique extremely thin cells (ETC) containing atomic vapour of alkali metals with the column thickness L of an order and much less than optical light wavelength λ have been developed. It has been demonstrated that these ETC are a very promising tool for a fundamental study of atom-light, atom-atom, atom-surface and atom-external magnetic field interactions. Particularly, a dramatically different behaviour of resonant absorption, fluorescence and resonant magneto-optical processes compared to that obtained with the help of cm-long ordinary cells has been demonstrated. Possible applications based on ETC are described, such as magnetometers with nanometric spatial resolution and tunabl…

Sub-Doppler features of optical processes in the Rb extremely thin cell filled with an additional buffer gas.

International audience; Comparison of the resonant absorption and fluorescence in the extremely thin cell (ETC) filled with pure Rb with another one filled with Rb and Neon gas with the pressures 6 Torr and 20 Torr is provided. The effect of the collapse and revival of Dicke-type narrowing is still observable for the thickness L=λ/2, and L=λ, where λ is a resonant laser wavelength 794 nm (D1 line of the Rb), i.e. the spectra of the resonant absorption and fluorescence demonstrate the sub-Doppler narrowing for the thickness L=λ/2 and broadening for the thickness L=λ. It is important to note, that in an ordinary Rb cell with the thickness L in the range of 1mm- 10 cm filled with buffer gas, w…

ATOM-WALL COLLISIONS INFLUENCE ON DARK-LINE ATOMIC RESONANCES IN SUBMICRON THIN VAPOUR CELLS

Symmetry breaking exhibition by magnetic field induced explicit circular dichroism

In this letter we demonstrate universal symmetry breaking by means of magnetically induced circular dichroism. Magnetic field induces forbidden at zero field atomic transitions between $\Delta F = \pm2$ hyperfine levels. In a particular range of magnetic field, intensities of these transitions experience significant enhancement. We have deduced a general rule applicable for the $D_2$ lines of all bosonic alkali atoms, that is transition intensity enhancement is larger for the case of $\sigma^+$ than for $\sigma^-$ excitation for $\Delta F = +2$, whereas it is larger (e.g. up to $10^{11}$ times for $^{85}$Rb atoms) in the case of $\sigma^-$ than for $\sigma^+$ polarization for $\Delta F = -2…

Dark-line Atomic Resonances in 1-100 µm-thin cells

International audience; Recently developed micrometric thin cells (MTC) containing atomic vapor of micrometric column thickness allow one to study peculiarities of Electromagnetically Induced Transparency (EIT) phenomenon, along with the accompanying velocity selective optical pumping/saturation (VSOP) resonances. MTC are filled with pure Rb and neither buffer gas nor paraffin-coated walls were used. the Lambda-system on D2 lines of 85RB have been studied with the use of two separate diode lasers. There are several dramatic distinctions in formation of EIT and VSOP resonances in MTC as compared with conventional cm-size cells. Particularly, in the case of MTC the narrowest EIT resonance is …

Study of electromagnetically induced transparency in strong magnetic field using Rb nanometric-thin cell.

Saturated absorption spectroscopy: elimination of crossover resonances by use of a nanocell

It is demonstrated that velocity selective optical pumping/saturation resonances of reduced absorption in a Rb vapor nanocell with thickness \textit{L=} $\lambda $, 2$\lambda $, and 3$\lambda $ (resonant wavelength $\lambda $ = 780 nm) allow the complete elimination of crossover (CO) resonances. We observe well pronounced resonances corresponding to the F$_{g}=3$ $\to $ F$_{e}=2,3,4$ hyperfine transitions of the $^{85}$Rb D$_{2}$ line with linewidths close to the natural width. A small CO resonance located midway between F$_{g}=3$ $\to $ F$_{e}=3$ and F$_{g}=3$ $\to$ F$_{e}=4$ transitions appears only for \textit{L} = 4$\lambda $. The D$_{2}$ line ($\lambda $ = 852 nm) in a Cs nanocell exhi…

Approach to quantitative spectroscopy of atomic vapor in optical nanocells

We present a method for recovery of narrow homogeneous spectral features out of a broad inhomogeneous overlapped profile based on second-derivative processing of the absorption spectra of alkali metal atomic vapor nanocells. The method is shown to preserve the frequency positions and amplitudes of spectral transitions, thus being applicable for quantitative spectroscopy. The proposed technique was successfully applied and tested for measurements of hyperfine splitting and atomic transition probabilities, development of an atomic frequency reference, determination of isotopic abundance, study of atom-surface interaction, and determination of magnetic-field-induced modification of atomic tran…

Saturation effects of Faraday rotation signals in Cs vapor nanocells: thickness-dependent effects.

Dark-Line Atomic Resonances in Micrometric Rb-Vapor Layer

We present measurements of dark-line resonances excited in Rb atomic vapor confined in micrometric cells (MC). In our work, the Lambda-systems on D2 line of 85Rb have been studied with the use of bi-chromatic radiation of two separate narrowband diode lasers.

Sub-Doppler Satellites of Dark-Line Atomic Resonances in the Case of Ordinary Vapour Cell and Extremely Thin Cell

Coherent population trapping effect in sub-micron thin Rb-vapor layer.

International audience

Ladder and lambda systems: electromagnetically induced transparency in thin and extremely-thin cells.

QUANTITATIVE SPECTROSCOPY OF Rb ATOMS IN STRONG MAGNETIC FIELD BASED ON SUBMICRON THIN VAPOUR.

The energy levels of atoms placed in an external magnetic field undergo frequency shifts and changes in their transition probabilities. It is demonstrated that using fluorescence spectra from a submicron thin vapour cell (STC) with the thickness L = λ/2, it is possible to efficiently study the above mentioned changes (“half-λ Zeeman technique” (HLZT)). The circularly polarized beam of extended-cavity diode laser (λ = 794 nm, laser bandwidth γL < 1 MHz) resonant with 87Rb D1 transition, after passing through Faraday isolator is directed onto the Rb STC with the thickness L = λ/2. The temperature of the STC is 120 °C, corresponding to N ~ 1013 atom/cm3. STC was provided by a special oven with…

Peculiarities of resonant absorption on D lines of Cs and Rb for atomic vapour layer of order of light wavelength.

high-contrast dark-line atomic resonance of D1 excitation in nanometric-thin cell filled with rubidium