Chinese Physics

Theoretical analysis of cavity saturation spectroscopy of weak molecular absorbance

Weiguang Ma, Lei Dong, Yin Wang-Bao, Jia Suo-Tang

Published Mar 17, 2005• 2 citations

Abstract

A theoretical analysis of sub-Doppler molecular saturation spectroscopy by use of a confocal Fabry–Perot (CFP) cavity is presented. The effects of gas pressure, cavity length and mirror reflectivity on the saturation dip amplitude are analysed. Such a treatment can provide the optimum conditions and a guidance for the experiment of saturating the weak molecular absorption lines.

DOI: 10.1088/1009-1963/14/4/012

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Chinese Physics

Theoretical analysis of cavity saturation spectroscopy of weak molecular absorbance

Weiguang Ma, Lei Dong, Yin Wang-Bao, Jia Suo-Tang

Published Mar 17, 2005• 2 citations

Publisher

Abstract

DOI: 10.1088/1009-1963/14/4/012

Related papers

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Chinese Physics BMar 28, 20050 citations

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А. Ч. Измайлов

We have studied theoretically nontrivial specific features of sub-Doppler resonances of saturated absorption in a multilayer gas cell with a rarefied gas medium, which is a compact analog of a large number of plane-parallel atomic beams. Spatially separated saturating and probing monochromatic laser beams that co- and counterpropagate (at the same frequency) in this cell have been considered. In this situation, the action of the light radiation of the saturating beam on the probing beam is determined by optically pumped atoms that fly between the beams under conditions that the longitudinal components of their velocities experience selection due to a specific geometry of the multilayer cell. Such a selection leads to a narrowing of the sub-Doppler resonance in the absorption of the probing beam and decreases the difference between the structures of this resonance for the cases of co- and counterpropagation of the saturating radiation. We have found that, in the considered multilayer cell, the effective width of the sub-Doppler resonance can be smaller (by a factor of about 1.5) than the extremely narrow characteristic width of the well-known Lamb dip in spectroscopy of saturated absorption in the standard gas cell. Results of this study can be used in atomic spectroscopy of ultrahigh resolution and for the laser-frequency stabilization.We have studied theoretically nontrivial specific features of sub-Doppler resonances of saturated absorption in a multilayer gas cell with a rarefied gas medium, which is a compact analog of a large number of plane-parallel atomic beams. Spatially separated saturating and probing monochromatic laser beams that co- and counterpropagate (at the same frequency) in this cell have been considered. In this situation, the action of the light radiation of the saturating beam on the probing beam is determined by optically pumped atoms that fly between the beams under conditions that the longitudinal components of their velocities experience selection due to a specific geometry of the multilayer cell. Such a selection leads to a narrowing of the sub-Doppler resonance in the absorption of the probing beam and decreases the difference between the structures of this resonance for the cases of co- and counterpropagation of the saturating radiation. We have found that, in the considered multilayer cell, the effective width of the sub-Doppler resonance can be smaller (by a factor of about 1.5) than the extremely narrow characteristic width of the well-known Lamb dip in spectroscopy of saturated absorption in the standard gas cell. Results of this study can be used in atomic spectroscopy of ultrahigh resolution and for the laser-frequency stabilization.

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Saturation effects affecting absorption and fluorescence spectra of an atomic vapor confined in an extremely thin cell (cell thickness $L<1\phantom{\rule{0.3em}{0ex}}\ensuremath{\mu}\mathrm{m}$) are investigated experimentally and theoretically. The study is performed on the ${D}_{2}$ line $(\ensuremath{\lambda}=852\phantom{\rule{0.3em}{0ex}}\mathrm{nm})$ of Cs and concentrates on the two situations $L=\ensuremath{\lambda}∕2$ and $L=\ensuremath{\lambda}$, the most contrasted ones with respect to the length dependence of the coherent Dicke narrowing. For $L=\ensuremath{\lambda}∕2$, the Dicke-narrowed absorption profile simply broadens and saturates in amplitude when increasing the light intensity, while for $L=\ensuremath{\lambda}$, sub-Doppler dips of reduced absorption at the line-center appear on the broad absorption profile. For a fluorescence detection at $L=\ensuremath{\lambda}$, saturation induces narrow dips, but only for hyperfine components undergoing a population loss through optical pumping. These experimental results are interpreted with the help of the various existing models and are compared with numerical calculations based upon a two-level modeling that considers both a closed and an open system.Saturation effects affecting absorption and fluorescence spectra of an atomic vapor confined in an extremely thin cell (cell thickness $L<1\phantom{\rule{0.3em}{0ex}}\ensuremath{\mu}\mathrm{m}$) are investigated experimentally and theoretically. The study is performed on the ${D}_{2}$ line $(\ensuremath{\lambda}=852\phantom{\rule{0.3em}{0ex}}\mathrm{nm})$ of Cs and concentrates on the two situations $L=\ensuremath{\lambda}∕2$ and $L=\ensuremath{\lambda}$, the most contrasted ones with respect to the length dependence of the coherent Dicke narrowing. For $L=\ensuremath{\lambda}∕2$, the Dicke-narrowed absorption profile simply broadens and saturates in amplitude when increasing the light intensity, while for $L=\ensuremath{\lambda}$, sub-Doppler dips of reduced absorption at the line-center appear on the broad absorption profile. For a fluorescence detection at $L=\ensuremath{\lambda}$, saturation induces narrow dips, but only for hyperfine components undergoing a population loss through optical pumping. These experimental results are interpreted with the help of the various existing models and are compared with numerical calculations based upon a two-level modeling that considers both a closed and an open system.

arXiv:0706.0837Physical Review AJul 31, 200760 citations

Saturated absorption in NH3 demonstrated using a tuneable diode laser

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Applied Physics LettersSep 15, 197819 citations

{D}_{2}

line $(\ensuremath{\lambda}=852\phantom{\rule{0.3em}{0ex}}\mathrm{nm})$ of Cs and concentrates on the two situations $L=\ensuremath{\lambda}∕2$ and $L=\ensuremath{\lambda}$, the most contrasted ones with respect to the length dependence of the coherent Dicke narrowing. For $L=\ensuremath{\lambda}∕2$, the Dicke-narrowed absorption profile simply broadens and saturates in amplitude when increasing the light intensity, while for $L=\ensuremath{\lambda}$, sub-Doppler dips of reduced absorption at the line-center appear on the broad absorption profile. For a fluorescence detection at $L=\ensuremath{\lambda}$, saturation induces narrow dips, but only for hyperfine components undergoing a population loss through optical pumping. These experimental results are interpreted with the help of the various existing models and are compared with numerical calculations based upon a two-level modeling that considers both a closed and an open system.