Comparison of absorption and fluorescence in a nano-cell containing Rb vapor with other Rb nano-cells with addition of
neon gas is presented. It is shown that the effect of collapse and revival of Dicke-type narrowing occurs for Rb nanocells
containing N2 as buffer gas under 6 and 20 Torr pressure for the thickness L = λ /2 and L = where λ is the resonant λ,
laser wavelength 794 nm (D1 line). Particularly for 6 Torr the line-width of the transmission spectrum for the thickness L
=λ/2 is 2 times narrower than that for L = λ. For an ordinary Rb cell with L = 0.1 - 10 cm with addition of buffer gas, the
velocity selective optical pumping/saturation (VSOP) resonances in saturated absorption spectra are fully suppressed
when the buffer gas pressure > 0.5 Torr. A spectacular difference is that for L = λ, VSOP resonances located at the
atomic transitions are still observable even when Ne pressure is ≥ 6 Torr. Narrowband fluorescence spectra of a nano-cell
with L = λ/2 can be used as a convenient tool for online buffer gas pressure monitoring for the conditions when ordinary
pressure gauges are unusable. Comparison of electromagnetically induced transparency (EIT) effect in a nano-cell filled
with pure (without a buffer gas) Rb with another nano-cell, where buffer gas nitrogen is added, is presented. The use of
N2 gas inside Rb nano-cells strongly extends the range of coupling laser detunings in which it is still possible to form
EIT resonance.
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