Physical Review Applied

Effect of Depolarizing and Quenching Collisions on the Contrast of Coherent Population Trapping Resonance

Kirill M. Sabakar, Maria I. Vaskovskaya, Dmitry S. Chuchelov, Eugene A. Tsygankov, Vitali V. Vassiliev, Sergei A. Zibrov, Vladimir L Velichansky

Published Sep 8, 2023• 6 citations

Publisher

Abstract

We investigate the effect of buffer gases on the coherent population trapping resonance induced by a $\ensuremath{\sigma}$-polarized optical field in ${}^{87}\mathrm{Rb}$ atoms. Our experimental results show that inert gases, which depolarize the excited state of alkali-metal atoms, provide higher contrast than nitrogen that effectively quenches their fluorescence. We also demonstrate that elimination of spontaneous radiation does not significantly decrease the width at moderate temperatures of an atomic medium. Therefore, a mixture of inert gases can be preferable over a mixture with nitrogen for atomic clocks.

DOI: 10.1103/physrevapplied.20.034015

Related papers

Effect of depolarizing and quenching collisions on contrast of the coherent population trapping resonance

Kirill M. Sabakar, Maria I. Vaskovskaya, Dmitry S. Chuchelov +4 more

arXiv:2305.00761May 1, 20230 citations

Contrast of Ramsey-CPT Fringes in Quenching and Depolarizing Gases

Dmitry S. Chuchelov, Maria I. Vaskovskaya, Eugene A. Tsygankov +4 more

Journal of Experimental and Theoretical Physics LettersDec 25, 20233 citations

Coherent population trapping resonances in potassium with amplitude-modulated light

Silvia Gozzini, Luca Marmugi, Dimitar G. Slavov +2 more

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIEOct 8, 20103 citations

Three-photon-absorption resonance for all-optical atomic clocks

Sergei A. Zibrov, Irina V. Novikova, David F. Phillips +4 more

arXiv:physics/0501090Physical Review AJul 7, 200537 citations

Experimental Evidence for the Absence of Quenching of Sodium Resonance Radiation by Inert Gases

G. H. Copley, B P Kibble, L. Krause

Physical ReviewNov 5, 196736 citations

High-resolution studies of collision-induced population grating resonances in optical four-wave mixing in sodium vapor

Lewis J. Rothberg, N. Bloembergen

Physical Review ANov 1, 198436 citations

Physical Review Applied

Effect of Depolarizing and Quenching Collisions on the Contrast of Coherent Population Trapping Resonance

Kirill M. Sabakar, Maria I. Vaskovskaya, Dmitry S. Chuchelov, Eugene A. Tsygankov, Vitali V. Vassiliev, Sergei A. Zibrov, Vladimir L Velichansky

Published Sep 8, 2023• 6 citations

Publisher

Abstract

We investigate the effect of buffer gases on the coherent population trapping resonance induced by a

\ensuremath{\sigma}

-polarized optical field in

{}^{87}\mathrm{Rb}

atoms. Our experimental results show that inert gases, which depolarize the excited state of alkali-metal atoms, provide higher contrast than nitrogen that effectively quenches their fluorescence. We also demonstrate that elimination of spontaneous radiation does not significantly decrease the width at moderate temperatures of an atomic medium. Therefore, a mixture of inert gases can be preferable over a mixture with nitrogen for atomic clocks.

DOI: 10.1103/physrevapplied.20.034015

Related papers

Effect of depolarizing and quenching collisions on contrast of the coherent population trapping resonance

Kirill M. Sabakar, Maria I. Vaskovskaya, Dmitry S. Chuchelov +4 more

We investigate the effect of buffer gases on the coherent population trapping resonance induced by a $σ$ -polarized optical field in $^{87}$ Rb atoms. Our experimental results show that inert gases, which depolarize the excited state of the alkali-metal atoms, provide higher contrast than nitrogen that effectively quenches their fluorescence. We also demonstrate that elimination of the spontaneous radiation does not significantly decrease the width at moderate temperatures of an atomic medium. Therefore, a mixture of inert gases can be preferable over a mixture with nitrogen for atomic clocks.We investigate the effect of buffer gases on the coherent population trapping resonance induced by a $σ$-polarized optical field in $^{87}$Rb atoms. Our experimental results show that inert gases, which depolarize the excited state of the alkali-metal atoms, provide higher contrast than nitrogen that effectively quenches their fluorescence. We also demonstrate that elimination of the spontaneous radiation does not significantly decrease the width at moderate temperatures of an atomic medium. Therefore, a mixture of inert gases can be preferable over a mixture with nitrogen for atomic clocks.

arXiv:2305.00761May 1, 20230 citations

Contrast of Ramsey-CPT Fringes in Quenching and Depolarizing Gases

Dmitry S. Chuchelov, Maria I. Vaskovskaya, Eugene A. Tsygankov +4 more

Molecular nitrogen is often used as a buffer gas in cells with alkali metals due to its known ability to quench resonant fluorescence. It is widely believed that the suppression of spontaneous emission decreases the width of coherent population trapping resonance. However, our recent results have not confirmed this positive action of molecular nitrogen within the typical range of 87Rb concentrations and buffer gas pressures. On the opposite, we have observed the negative influence of quenching, the decrease in contrast of the coherent population trapping resonance in ${{\sigma }^{ + }}$ – ${{\sigma }^{ + }}$ configuration. In this work, we further confirm these results implementing the Ramsey spectroscopy, and compare the characteristics of the central fringe in nitrogen and neon, and show that the latter provides a significantly better contrast-to-width ratio.Molecular nitrogen is often used as a buffer gas in cells with alkali metals due to its known ability to quench resonant fluorescence. It is widely believed that the suppression of spontaneous emission decreases the width of coherent population trapping resonance. However, our recent results have not confirmed this positive action of molecular nitrogen within the typical range of 87Rb concentrations and buffer gas pressures. On the opposite, we have observed the negative influence of quenching, the decrease in contrast of the coherent population trapping resonance in $${{\sigma }^{ + }}$$ – $${{\sigma }^{ + }}$$ configuration. In this work, we further confirm these results implementing the Ramsey spectroscopy, and compare the characteristics of the central fringe in nitrogen and neon, and show that the latter provides a significantly better contrast-to-width ratio.

Journal of Experimental and Theoretical Physics LettersDec 25, 20233 citations

Coherent population trapping resonances in potassium with amplitude-modulated light

Silvia Gozzini, Luca Marmugi, Dimitar G. Slavov +2 more

We present the results of an experimental study of Coherent Population Trapping (CPT) in potassium, obtained by means of modulation of laser light amplitude with kHz frequency. The radiation from an external cavity diode laser, matching the D1 line of K, is modulated by an acousto-optical modulator. In the cell containing buffer gas, the CPT resonance width is reduced more than three orders of magnitude as compared to the cell containing pure potassium vapor. In K this resonance narrowing occurs with high resonance contrast; such behavior is not observed in buffered cells containing Rb or Cs, where the optical pumping to the non-interacting with the light ground level is very effective and depletes the population of the working ground Zeeman sublevels. The narrow CPT resonance of reduced fluorescence transforms to the one of enhanced fluorescence with the cell temperature rising. The transformed resonance exhibits higher contrast and lower width than those of the reduced fluorescence resonance. Hence, beside its scientific importance the resonance sign reversal can be used for the improvement of the CPT resonance parameters.We present the results of an experimental study of Coherent Population Trapping (CPT) in potassium, obtained by means of modulation of laser light amplitude with kHz frequency. The radiation from an external cavity diode laser, matching the D1 line of K, is modulated by an acousto-optical modulator. In the cell containing buffer gas, the CPT resonance width is reduced more than three orders of magnitude as compared to the cell containing pure potassium vapor. In K this resonance narrowing occurs with high resonance contrast; such behavior is not observed in buffered cells containing Rb or Cs, where the optical pumping to the non-interacting with the light ground level is very effective and depletes the population of the working ground Zeeman sublevels. The narrow CPT resonance of reduced fluorescence transforms to the one of enhanced fluorescence with the cell temperature rising. The transformed resonance exhibits higher contrast and lower width than those of the reduced fluorescence resonance. Hence, beside its scientific importance the resonance sign reversal can be used for the improvement of the CPT resonance parameters.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIEOct 8, 20103 citations

Three-photon-absorption resonance for all-optical atomic clocks

Sergei A. Zibrov, Irina V. Novikova, David F. Phillips +4 more

We report an experimental study of an all-optical three-photon-absorption resonance (known as an `` $N$ resonance'') and discuss its potential application as an alternative to atomic clocks based on coherent population trapping. We present measurements of the $N$ -resonance contrast, width and light shift for the ${D}_{1}$ line of $^{87}\mathrm{Rb}$ with varying buffer gases, and find good agreement with an analytical model of this resonance. The results suggest that $N$ resonances are promising for atomic clock applications.We report an experimental study of an all-optical three-photon-absorption resonance (known as an ``$N$ resonance'') and discuss its potential application as an alternative to atomic clocks based on coherent population trapping. We present measurements of the $N$-resonance contrast, width and light shift for the ${D}_{1}$ line of $^{87}\mathrm{Rb}$ with varying buffer gases, and find good agreement with an analytical model of this resonance. The results suggest that $N$ resonances are promising for atomic clock applications.

arXiv:physics/0501090Physical Review AJul 7, 200537 citations

Experimental Evidence for the Absence of Quenching of Sodium Resonance Radiation by Inert Gases

G. H. Copley, B P Kibble, L. Krause

An upper limit of ${10}^{\ensuremath{-}2}$ ${\mathrm{\AA{}}}^{2}$ is obtained for the quenching cross section of sodium resonance fluorescence when the excited sodium atoms are in collision with inert-gas atoms in their ground state. Excitation of sodium vapor at a pressure of 5\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}7}$ Torr is followed by observation of the decay of the fluorescence using the method of delayed coincidences. The decay time of the fluorescence is unaffected by the presence of the inert gases He, Ne, A, Kr, and Xe at pressures up to 800 Torr, and at temperatures of 130 and 210\ifmmode^\circ\else\textdegree\fi{}C.An upper limit of ${10}^{\ensuremath{-}2}$ ${\mathrm{\AA{}}}^{2}$ is obtained for the quenching cross section of sodium resonance fluorescence when the excited sodium atoms are in collision with inert-gas atoms in their ground state. Excitation of sodium vapor at a pressure of 5\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}7}$ Torr is followed by observation of the decay of the fluorescence using the method of delayed coincidences. The decay time of the fluorescence is unaffected by the presence of the inert gases He, Ne, A, Kr, and Xe at pressures up to 800 Torr, and at temperatures of 130 and 210\ifmmode^\circ\else\textdegree\fi{}C.

Physical ReviewNov 5, 196736 citations

High-resolution studies of collision-induced population grating resonances in optical four-wave mixing in sodium vapor

Lewis J. Rothberg, N. Bloembergen

Optical four-wave mixing resonances in sodium vapor induced by collisions with inert buffer gases (He, Ar, Xe, ${\mathrm{N}}_{2}$ ) are characterized at high resolution ( 5 MHz) using lasers tuned near the $D$ lines of Na. These resonances are interpreted in terms of coherent scattering from a population grating established by collisional absorption of the incident radiation. The roles of homogeneous and inhomogeneous contributions to the resonance line shapes are clarified. The line shapes exhibit structure sharper than the predicted linewidth, that characteristic of the $3P$ -to- $3S$ transition rate. We show that this is caused by collision-induced optical pumping which introduces the ground-state lifetime into the grating relaxation physics. These long-lived gratings are exemplified dramatically by experiments in the presence of ${\mathrm{N}}_{2}$ which collisionally quenches the Na $3P$ states. Similar results are obtained in Xe where it is argued that excimer formation with the $3P$ states plays a role in the population dynamics. Model calculations of the effects of sodium level degeneracy on the grating dynamics are presented to support these conclusions. Finally we present data illustrating interference between the collision-induced population grating resonances detailed here and collision-induced coherent Raman resonances between Zeeman sublevels of the ground state.Optical four-wave mixing resonances in sodium vapor induced by collisions with inert buffer gases (He, Ar, Xe, ${\mathrm{N}}_{2}$) are characterized at high resolution ( 5 MHz) using lasers tuned near the $D$ lines of Na. These resonances are interpreted in terms of coherent scattering from a population grating established by collisional absorption of the incident radiation. The roles of homogeneous and inhomogeneous contributions to the resonance line shapes are clarified. The line shapes exhibit structure sharper than the predicted linewidth, that characteristic of the $3P$-to-$3S$ transition rate. We show that this is caused by collision-induced optical pumping which introduces the ground-state lifetime into the grating relaxation physics. These long-lived gratings are exemplified dramatically by experiments in the presence of ${\mathrm{N}}_{2}$ which collisionally quenches the Na $3P$ states. Similar results are obtained in Xe where it is argued that excimer formation with the $3P$ states plays a role in the population dynamics. Model calculations of the effects of sodium level degeneracy on the grating dynamics are presented to support these conclusions. Finally we present data illustrating interference between the collision-induced population grating resonances detailed here and collision-induced coherent Raman resonances between Zeeman sublevels of the ground state.

Physical Review ANov 1, 198436 citations

We investigate the effect of buffer gases on the coherent population trapping resonance induced by a

\ensuremath{\sigma}

-polarized optical field in

{}^{87}\mathrm{Rb}

We investigate the effect of buffer gases on the coherent population trapping resonance induced by a

σ

-polarized optical field in

^{87}

Rb atoms. Our experimental results show that inert gases, which depolarize the excited state of the alkali-metal atoms, provide higher contrast than nitrogen that effectively quenches their fluorescence. We also demonstrate that elimination of the spontaneous radiation does not significantly decrease the width at moderate temperatures of an atomic medium. Therefore, a mixture of inert gases can be preferable over a mixture with nitrogen for atomic clocks.

{{\sigma }^{ + }}

–

{{\sigma }^{ + }}

configuration. In this work, we further confirm these results implementing the Ramsey spectroscopy, and compare the characteristics of the central fringe in nitrogen and neon, and show that the latter provides a significantly better contrast-to-width ratio.

We report an experimental study of an all-optical three-photon-absorption resonance (known as an ``

N

resonance'') and discuss its potential application as an alternative to atomic clocks based on coherent population trapping. We present measurements of the

N

-resonance contrast, width and light shift for the

{D}_{1}

line of

^{87}\mathrm{Rb}

with varying buffer gases, and find good agreement with an analytical model of this resonance. The results suggest that

N

resonances are promising for atomic clock applications.

An upper limit of ${10}^{\ensuremath{-}2}$

{\mathrm{\AA{}}}^{2}

is obtained for the quenching cross section of sodium resonance fluorescence when the excited sodium atoms are in collision with inert-gas atoms in their ground state. Excitation of sodium vapor at a pressure of 5\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}7}$ Torr is followed by observation of the decay of the fluorescence using the method of delayed coincidences. The decay time of the fluorescence is unaffected by the presence of the inert gases He, Ne, A, Kr, and Xe at pressures up to 800 Torr, and at temperatures of 130 and 210\ifmmode^\circ\else\textdegree\fi{}C.

Optical four-wave mixing resonances in sodium vapor induced by collisions with inert buffer gases (He, Ar, Xe,

{\mathrm{N}}_{2}

) are characterized at high resolution ( 5 MHz) using lasers tuned near the

D

lines of Na. These resonances are interpreted in terms of coherent scattering from a population grating established by collisional absorption of the incident radiation. The roles of homogeneous and inhomogeneous contributions to the resonance line shapes are clarified. The line shapes exhibit structure sharper than the predicted linewidth, that characteristic of the

3P

-to-

3S

transition rate. We show that this is caused by collision-induced optical pumping which introduces the ground-state lifetime into the grating relaxation physics. These long-lived gratings are exemplified dramatically by experiments in the presence of

{\mathrm{N}}_{2}

which collisionally quenches the Na

3P

states. Similar results are obtained in Xe where it is argued that excimer formation with the

3P

states plays a role in the population dynamics. Model calculations of the effects of sodium level degeneracy on the grating dynamics are presented to support these conclusions. Finally we present data illustrating interference between the collision-induced population grating resonances detailed here and collision-induced coherent Raman resonances between Zeeman sublevels of the ground state.