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Doppler-free nonlinear faraday rotatior spectroscopy of rb atoms

Rafael Drampyan, Andrew D. Greentree, Durrant, A.V

Published Jan 1, 2009• 0 citations
OpenAlex

Abstract

The aim of this book is to present new results in rapidly developing fields of nonlinear optics such as atomic coherence, magneto-optics of atomic media, Doppler-free spectroscopy, time-domain spectroscopy of dense atomic vapors, frequency comb spectroscopy and atom-surface interactions. The discovery of such coherent effects as coherent population trapping (CPT), electromagnetically induced transparency (EIT) and electromagnetically induced absorption (EIA) opened a new avenue for development in many fields of nonlinear optics. Investigations during the last decade have shown many related new results and approaches in nonlinear optics. These include nonlinear magneto-optical processes (NMOP) in the context of high precision magnetometry, quantum information storage and processing, magnetic resonance imaging and magnetic particle detection; the use of ultra-thin (nanometric length) atomic vapor cells in magneto-optical experiments, which show new peculiarities of both coherent effects and NMOP; the use of frequency and amplitude modulated laser beams for NMOP studies in atomic vapors with the aim of extending the range of ultra-precise magnetometers to stronger, particularly geomagnetic fields; application of the counter-propagating beam technique to reveal the Doppler free nonlinear Faraday rotation signals, as a spectroscopic tool and for applications; enhanced nonlinearity due to atomic coherence in multi-state systems; experimental study of EIT in solids; the use of the phase stabilized frequency domain combs of femtosecond laser pulses for velocity selective optical pumping of atomic hyperfine levels, as a direct frequency comb spectroscopy; time-domain nonlinear spectroscopy of dense atomic vapors; atom-surface interactions and laser induced adsorption and desorption of alkali atoms on the surface of solid materials for nanotechnology applications

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The subject of this thesis is the study of coherent interaction of light with matter (atoms) to improve the precision measurements and techniques. Special attention is drawn to get the narrow subnatural electromagnetically induced transmission (EIT), electromagnetically induced absorption (EIA) and nonlinear magneto-optic rotation (NMOR) caused by alkali atoms contained in a vapor cell. Subnatural polarization rotation introduces by a strong circularly polarized light in the absence of any external magnetic field was also studied. A detailed theoretical treatment, given in this dissertation, allows to associate each of the features of the spectra with a special physical mechanism. Many quantum phenomena related to interferences, coherences, optical pumping etc. experiments are studied using home-built diode lasers. This thesis also describes laser cooling and trapping of rubidium atoms using two techniques. Deflection of cold atoms horizontally from MOT using pushing beams are discussed in close consideration for the improvements in the precision measurements. This thesis is organized as follows. In Chapter 1, an introduction to the importance of sub-natural narrow resonance and simplified technique in the precision measurement will be discussed. In Chapter 2, an introduction to EIT, EIA and NMOR resonance are discussed. This chapter will provide a basic theoretical background of atom-field interactions, especially for Λ-type and N -type systems and its steady state solution using density matrix analysis and experimental tools. The most important notion of laser cooling of atoms, ions or molecule i.e., exchange of momentum between light and atoms combining with the Doppler effect will be discussed. In Chapter 3, the observation of subnatural EIT and subnatural EIA in closed and open degenerate two-level system using room temperature vapor cell filled with Rb will be presented. Physical mechanisms that contribute to EIT and EIA, and the contrast of our results from the coherent population trapping (CPT)–type resonances are discussed in detail in appendix A.2 according to our experimental results. In Chapter 4, the narrowing of subnatural EIT and subnatural EIA linewidth in closed and open systems again in degenerate two level transition, using the “Laguerre-Gaussian” control beam instead of generally studied Gaussian beam, will be discussed in detail. In Chapter 5, the conversion between subnatural EIT to subnatural EIA in a degenerate Λ system will be discussed. The physical mechanism created by the introduction of a coherent counter propagating control laser to the co-propagating probe and the control laser are studied. The effect of polarization and axial velocity Doppler averaging will also be studied. In Chapter 6, we will discuss the sensitive technique for precise measurement of small magnetic fields using the NMOR, by chopping the resonant laser beam. We will study the sensitivity and the potential application of this technique in the measurement of an atomic electric-dipole moment. In Chapter 7, we will…

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Alkali metals have played an important role in optical and atomic physics from the very beginning. This thesis deals with three aspects and applications of alkali-metal atoms, in particular rubidium (Rb). Optical pumping changes both the amplitudes and the center positions of the absorption profiles in the Doppler-broadened D-line spectra of the alkali-metal atoms. This effect has been studied by reducing the multilevel system to an effective three-level system and by treating the finite interaction time and collisions with the vapor-cell walls in two different ways: as ground-state relaxation and by averaging the time-dependent absorption over the distribution of interaction times. The former is a computationally efficient way to compare theoretical spectra to experimental results, and the latter reveals lineshape details that are due to the coupling between the Doppler shift and the interaction times through the longitudinal velocity of the atoms. Using coherent population trapping (CPT) in 85Rb, an all-optical atomic clock has been realized. The good noise properties of the diode laser, an optimized buffer gas, and a very low light intensity allow detection of ultranarrow CPT resonances < 20 Hz, apparently the narrowest optically induced hyperfine CPT resonance ever measured. The Q value of this resonance, 1.5 × 108, is comparable to Q values in cesium clocks and the stability of the CPT clock is sufficient for many high-precision applications. Trapping of Rb atoms in microscopic magneto-optical traps (MOTs) a few hundred micrometers from the surface of an optically transparent ferrite-garnet permanent-magnet atom chip has been demonstrated. The required magnetic fields are created by magnetic patterns magneto-optically written into the ferrite-garnet film and the transparency of the chip allows using a conventional MOT geometry. The magnetic patterns can be erased and re-written in situ, even during the experiments. Magnetic traps with a trap depth up to 1 mK could be realized using this type of atom chip.

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Optical atomic magnetometry

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This work presents new methods of optical magnetometry developed in the Center for Magneto-Optical Research at the Jagiellonian University. Using rubidium atoms contained in cm-long glass cells and amplitude-modulated laser we have recorded magneto-optical signals of extremely small widths. These signals allow measurements of magnetic fields with a sensitivity comparable to that achieved with magnetometers based on Superconducting Quantum Interference Devices (SQUIDs). Full Text: PDF References: M. Faraday,Experimental Researches in Electricity. Nineteenth Series, Trans. R. Soc. London 136, 1 (1846). [CrossRef] K. Barczak and S. Pustelny,Magnetooptic properties of special optical type D fibers, J. Phys. IV 137, 15 (2006). [CrossRef] W. Gawlik, J. Kowalski, R. Neumann, and F. Trager, Observation of the electric hexadecapole moment of free Na atoms in a forward scattering experiment, Opt. Commun. 12, 400 (1974). [CrossRef] W. Gawlik, S. Pustelny, in New Trends in Quantum Coherence and Optics, R. Drampyan Ed., 47 (New York, Nova Publishers, 2009). D. W. Gawlik, D. F. Kimball, S. M. Rochester, A. Weis, and V. V. Yashchuk,Resonant nonlinear magneto-optical effects in atoms, Rev. Mod. Phys. 74, 1153 (2002). [CrossRef] D. V.V. Yashchuk, and M. Zolotorev,Nonlinear Magneto-optic Effects with Ultranarrow Widths, Phys. Rev. Lett. 81(26), 5788 (1998). [CrossRef] D. D. F. Kimball, S. M. Rochester, V. V. Yashchuk, and M. Zolotorev,Sensitive magnetometry based on nonlinear magneto-optical rotation, Phys. Rev. A 62, 043403 (2000). [CrossRef] G. Wąsik, W. Gawlik, J. Zachorowski, and W. Zawadzki, Laser frequency stabilization by Doppler-free magnetic dichroism, Appl. Phys. B 75, 613 (2002). [CrossRef] W. Gawlik, L. Krzemien, S. Pustelny, D. Sangla, J. Zachorowski, M. Graf, A. O. Sushkov, and D. Budker, magneto-optical rotation with amplitude modulated light, Appl. Phys. Lett. 88 131108 (2006). [CrossRef] D. D. F. Kimball, V. V. Yashchuk, M. Zolotorev,Nonlinear magneto-optical rotation with frequency-modulated light, Phys. Rev. A 65, 055403 (2002). [CrossRef] J. M. Higbie, E. Corsini, and D. Robust, high-speed, all-optical atomic magnetometer, Rev. Sci. Instr. 77, 113106 (2006). [CrossRef] S. Pustelny, A. Wojciechowski, M. Kotyrba, K. Sycz, J. Zachorowski, W. Gawlik, A. Cingoz, N. Leefer, J. M. Higbie, E. Corsini, M. P. Ledbetter, S. M. Rochester, A. O. Sushkov, and D. All-optical atomic magnetometers based on nonlinear magneto-optical rotation with amplitude modulated light, Proc. of SPIE 6604, 660404 (2007). [CrossRef] S. Pustelny, A. Wojciechowski, M. Gring, M. Kotyrba, J. Zachorowski, W. Gawlik, Magnetometry based on nonlinear magneto-optical rotation with amplitude-modulated light, J. Appl. Phys. 103, 063108 (2008). [CrossRef] S. Pustelny, S. M. Rochester, D. F. Jackson Kimball, V. V. Yashchuk, D. and W. Gawlik, Nonlinear magneto-optical rotation with modulated light in tilted magnetic fields, Phys. Rev. A 74, 063420 (2006). [CrossRef]

Photonics Letters of Poland•Mar 28, 2009•0 citations

Nonlinear optical effects manifested by electromagnetic induced transparency in cold atoms

Jiepeng Zhang

This dissertation reports experimental studies of nonlinear optical effects manifested by electromagnetically induced transparency (EIT) in cold Rb atoms. The cold Rb atoms are confined in a magneto-optic trap (MOT) obtained with the standard laser cooling and trapping technique. Because of the near zero Doppler shift and a high phase density, the cold Rb sample is well suited for studies of atomic coherence and interference and related applications, and the experiments can be compared quantitatively with theoretical calculations. It is shown that with EIT induced in the multi-level Rb system by laser fields, the linear absorption is suppressed and the nonlinear susceptibility is enhanced, which enables studies of nonlinear optics in the cold atoms with slow photons and at low light intensities. Three independent experiments are described and the experimental results are presented. First, an experimental method that can produce simultaneously co-propagating slow and fast light pulses is discussed and the experimental demonstration is reported. Second, it is shown that in a three-level Rb system coupled by multi-color laser fields, the multi-channel two-photon Raman transitions can be manipulated by the relative phase and frequency of a control laser field. Third, a scheme for all-optical switching near single photon levels is developed. The scheme is based on the phase-dependent multi-photon interference in a coherently coupled four-level system. The phase dependent multi-photon interference is observed and switching of a single light pulse by a control pulse containing ∼20 photons is demonstrated. These experimental studies reveal new phenomena manifested by quantum coherence and interference in cold atoms, contribute to the advancement of fundamental quantum optics and nonlinear optics at ultra-low light intensities, and may lead to the development of new techniques to control quantum states of atoms and photons, which will be useful for applications in quantum measurements and quantum photonic devices.

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Dmitry Budker, Donald J. Orlando, Valeriy V. Yashchuk

An experiment on nonlinear laser spectroscopy and magneto-optics at the Advanced Undergraduate Laboratory at Berkeley is described. The experiment consists of three parts. In the first part, students learn to operate a diode laser system and characterize its performance using a Fabry–Perot spectrum analyzer. In the second part, Doppler-broadened laser-induced fluorescence and Doppler-free saturated absorption spectra of the rubidium D2 line (780 nm) are recorded and analyzed. Finally, in the third part of the experiment, which we describe in greater detail, the near-resonant magneto-optical rotation is investigated. Nonlinear light-atom interaction leads to spectacular manifestations of the resonant Faraday effect—polarization plane rotation in a magnetic field applied along the direction of light propagation radically different from the linear case. In particular, narrow (∼30 Hz) effective line widths are observed in this experiment corresponding to a rotation enhancement by some seven orders of magnitude compared to the linear Faraday rotation.

American Journal of Physics•Jul 1, 1999•64 citations

Nonlinear Doppler-free spectroscopy of atoms near a surface

Pierre Simoneau, S. Le Boiteux, C. De Araujo +2 more

Up to now, Doppler-free nonlinear spectroscopy has been applied to atoms inside a gas medium (volume spectroscopy). We have extended these methods to atoms in the vicinity of a surface. The basic principle consists of monitoring reflectivity changes produced when a laser beam, incident on a glass–vapor interface, is brought into resonance with an atomic transition. For Doppler-free spectroscopy, two counterpropagating beams are used to operate velocity selection. If these two beams are under normal incidence in the glass—velocity selection perpendicular to the surface—one observes saturated dispersion (selective reflection sensitive to the real index). For incidence angles in the glass (prism) larger than the critical angle (total internal reflection), a standing evanescent wave is produced in the gas (velocity selection along the surface), and saturated absorption is detected. Experimental demonstration was performed on the Na resonance line; high sensitivity (10−4 relative reflectivity change) and spectral resolution as good as 20 MHz were obtained. The main limitation to better resolution comes from the short atomic transit time in the evanescent wave (typical extension ~λ). Relevant applications of these techniques should also concern the diagnostics of optically thick media, as analysis of interaction between gas-phase atoms and the surface, notably atom–wall collisions, and modification of the spontaneous emission characteristics.

International Laser Science Conference•Jan 1, 1986•0 citations
The aim of this book is to present new results in rapidly developing fields of nonlinear optics such as atomic coherence, magneto-optics of atomic media, Doppler-free spectroscopy, time-domain spectroscopy of dense atomic vapors, frequency comb spectroscopy and atom-surface interactions. The discovery of such coherent effects as coherent population trapping (CPT), electromagnetically induced transparency (EIT) and electromagnetically induced absorption (EIA) opened a new avenue for development in many fields of nonlinear optics. Investigations during the last decade have shown many related new results and approaches in nonlinear optics. These include nonlinear magneto-optical processes (NMOP) in the context of high precision magnetometry, quantum information storage and processing, magnetic resonance imaging and magnetic particle detection; the use of ultra-thin (nanometric length) atomic vapor cells in magneto-optical experiments, which show new peculiarities of both coherent effects and NMOP; the use of frequency and amplitude modulated laser beams for NMOP studies in atomic vapors with the aim of extending the range of ultra-precise magnetometers to stronger, particularly geomagnetic fields; application of the counter-propagating beam technique to reveal the Doppler free nonlinear Faraday rotation signals, as a spectroscopic tool and for applications; enhanced nonlinearity due to atomic coherence in multi-state systems; experimental study of EIT in solids; the use of the phase stabilized frequency domain combs of femtosecond laser pulses for velocity selective optical pumping of atomic hyperfine levels, as a direct frequency comb spectroscopy; time-domain nonlinear spectroscopy of dense atomic vapors; atom-surface interactions and laser induced adsorption and desorption of alkali atoms on the surface of solid materials for nanotechnology applications
The subject of this thesis is the study of coherent interaction of light with matter (atoms) to improve the precision measurements and techniques. Special attention is drawn to get the narrow subnatural electromagnetically induced transmission (EIT), electromagnetically induced absorption (EIA) and nonlinear magneto-optic rotation (NMOR) caused by alkali atoms contained in a vapor cell. Subnatural polarization rotation introduces by a strong circularly polarized light in the absence of any external magnetic field was also studied. A detailed theoretical treatment, given in this dissertation, allows to associate each of the features of the spectra with a special physical mechanism. Many quantum phenomena related to interferences, coherences, optical pumping etc. experiments are studied using home-built diode lasers. This thesis also describes laser cooling and trapping of rubidium atoms using two techniques. Deflection of cold atoms horizontally from MOT using pushing beams are discussed in close consideration for the improvements in the precision measurements. This thesis is organized as follows. In Chapter 1, an introduction to the importance of sub-natural narrow resonance and simplified technique in the precision measurement will be discussed. In Chapter 2, an introduction to EIT, EIA and NMOR resonance are discussed. This chapter will provide a basic theoretical background of atom-field interactions, especially for Λ-type and N -type systems and its steady state solution using density matrix analysis and experimental tools. The most important notion of laser cooling of atoms, ions or molecule i.e., exchange of momentum between light and atoms combining with the Doppler effect will be discussed. In Chapter 3, the observation of subnatural EIT and subnatural EIA in closed and open degenerate two-level system using room temperature vapor cell filled with Rb will be presented. Physical mechanisms that contribute to EIT and EIA, and the contrast of our results from the coherent population trapping (CPT)–type resonances are discussed in detail in appendix A.2 according to our experimental results. In Chapter 4, the narrowing of subnatural EIT and subnatural EIA linewidth in closed and open systems again in degenerate two level transition, using the “Laguerre-Gaussian” control beam instead of generally studied Gaussian beam, will be discussed in detail. In Chapter 5, the conversion between subnatural EIT to subnatural EIA in a degenerate Λ system will be discussed. The physical mechanism created by the introduction of a coherent counter propagating control laser to the co-propagating probe and the control laser are studied. The effect of polarization and axial velocity Doppler averaging will also be studied. In Chapter 6, we will discuss the sensitive technique for precise measurement of small magnetic fields using the NMOR, by chopping the resonant laser beam. We will study the sensitivity and the potential application of this technique in the measurement of an atomic electric-dipole moment. In Chapter 7, we will…
Alkali metals have played an important role in optical and atomic physics from the very beginning. This thesis deals with three aspects and applications of alkali-metal atoms, in particular rubidium (Rb). Optical pumping changes both the amplitudes and the center positions of the absorption profiles in the Doppler-broadened D-line spectra of the alkali-metal atoms. This effect has been studied by reducing the multilevel system to an effective three-level system and by treating the finite interaction time and collisions with the vapor-cell walls in two different ways: as ground-state relaxation and by averaging the time-dependent absorption over the distribution of interaction times. The former is a computationally efficient way to compare theoretical spectra to experimental results, and the latter reveals lineshape details that are due to the coupling between the Doppler shift and the interaction times through the longitudinal velocity of the atoms. Using coherent population trapping (CPT) in 85Rb, an all-optical atomic clock has been realized. The good noise properties of the diode laser, an optimized buffer gas, and a very low light intensity allow detection of ultranarrow CPT resonances < 20 Hz, apparently the narrowest optically induced hyperfine CPT resonance ever measured. The Q value of this resonance, 1.5 × 108, is comparable to Q values in cesium clocks and the stability of the CPT clock is sufficient for many high-precision applications. Trapping of Rb atoms in microscopic magneto-optical traps (MOTs) a few hundred micrometers from the surface of an optically transparent ferrite-garnet permanent-magnet atom chip has been demonstrated. The required magnetic fields are created by magnetic patterns magneto-optically written into the ferrite-garnet film and the transparency of the chip allows using a conventional MOT geometry. The magnetic patterns can be erased and re-written in situ, even during the experiments. Magnetic traps with a trap depth up to 1 mK could be realized using this type of atom chip.
This work presents new methods of optical magnetometry developed in the Center for Magneto-Optical Research at the Jagiellonian University. Using rubidium atoms contained in cm-long glass cells and amplitude-modulated laser we have recorded magneto-optical signals of extremely small widths. These signals allow measurements of magnetic fields with a sensitivity comparable to that achieved with magnetometers based on Superconducting Quantum Interference Devices (SQUIDs). Full Text: PDF References: M. Faraday,Experimental Researches in Electricity. Nineteenth Series, Trans. R. Soc. London 136, 1 (1846). [CrossRef] K. Barczak and S. Pustelny,Magnetooptic properties of special optical type D fibers, J. Phys. IV 137, 15 (2006). [CrossRef] W. Gawlik, J. Kowalski, R. Neumann, and F. Trager, Observation of the electric hexadecapole moment of free Na atoms in a forward scattering experiment, Opt. Commun. 12, 400 (1974). [CrossRef] W. Gawlik, S. Pustelny, in New Trends in Quantum Coherence and Optics, R. Drampyan Ed., 47 (New York, Nova Publishers, 2009). D. W. Gawlik, D. F. Kimball, S. M. Rochester, A. Weis, and V. V. Yashchuk,Resonant nonlinear magneto-optical effects in atoms, Rev. Mod. Phys. 74, 1153 (2002). [CrossRef] D. V.V. Yashchuk, and M. Zolotorev,Nonlinear Magneto-optic Effects with Ultranarrow Widths, Phys. Rev. Lett. 81(26), 5788 (1998). [CrossRef] D. D. F. Kimball, S. M. Rochester, V. V. Yashchuk, and M. Zolotorev,Sensitive magnetometry based on nonlinear magneto-optical rotation, Phys. Rev. A 62, 043403 (2000). [CrossRef] G. Wąsik, W. Gawlik, J. Zachorowski, and W. Zawadzki, Laser frequency stabilization by Doppler-free magnetic dichroism, Appl. Phys. B 75, 613 (2002). [CrossRef] W. Gawlik, L. Krzemien, S. Pustelny, D. Sangla, J. Zachorowski, M. Graf, A. O. Sushkov, and D. Budker, magneto-optical rotation with amplitude modulated light, Appl. Phys. Lett. 88 131108 (2006). [CrossRef] D. D. F. Kimball, V. V. Yashchuk, M. Zolotorev,Nonlinear magneto-optical rotation with frequency-modulated light, Phys. Rev. A 65, 055403 (2002). [CrossRef] J. M. Higbie, E. Corsini, and D. Robust, high-speed, all-optical atomic magnetometer, Rev. Sci. Instr. 77, 113106 (2006). [CrossRef] S. Pustelny, A. Wojciechowski, M. Kotyrba, K. Sycz, J. Zachorowski, W. Gawlik, A. Cingoz, N. Leefer, J. M. Higbie, E. Corsini, M. P. Ledbetter, S. M. Rochester, A. O. Sushkov, and D. All-optical atomic magnetometers based on nonlinear magneto-optical rotation with amplitude modulated light, Proc. of SPIE 6604, 660404 (2007). [CrossRef] S. Pustelny, A. Wojciechowski, M. Gring, M. Kotyrba, J. Zachorowski, W. Gawlik, Magnetometry based on nonlinear magneto-optical rotation with amplitude-modulated light, J. Appl. Phys. 103, 063108 (2008). [CrossRef] S. Pustelny, S. M. Rochester, D. F. Jackson Kimball, V. V. Yashchuk, D. and W. Gawlik, Nonlinear magneto-optical rotation with modulated light in tilted magnetic fields, Phys. Rev. A 74, 063420 (2006). [CrossRef]
This dissertation reports experimental studies of nonlinear optical effects manifested by electromagnetically induced transparency (EIT) in cold Rb atoms. The cold Rb atoms are confined in a magneto-optic trap (MOT) obtained with the standard laser cooling and trapping technique. Because of the near zero Doppler shift and a high phase density, the cold Rb sample is well suited for studies of atomic coherence and interference and related applications, and the experiments can be compared quantitatively with theoretical calculations. It is shown that with EIT induced in the multi-level Rb system by laser fields, the linear absorption is suppressed and the nonlinear susceptibility is enhanced, which enables studies of nonlinear optics in the cold atoms with slow photons and at low light intensities. Three independent experiments are described and the experimental results are presented. First, an experimental method that can produce simultaneously co-propagating slow and fast light pulses is discussed and the experimental demonstration is reported. Second, it is shown that in a three-level Rb system coupled by multi-color laser fields, the multi-channel two-photon Raman transitions can be manipulated by the relative phase and frequency of a control laser field. Third, a scheme for all-optical switching near single photon levels is developed. The scheme is based on the phase-dependent multi-photon interference in a coherently coupled four-level system. The phase dependent multi-photon interference is observed and switching of a single light pulse by a control pulse containing ∼20 photons is demonstrated. These experimental studies reveal new phenomena manifested by quantum coherence and interference in cold atoms, contribute to the advancement of fundamental quantum optics and nonlinear optics at ultra-low light intensities, and may lead to the development of new techniques to control quantum states of atoms and photons, which will be useful for applications in quantum measurements and quantum photonic devices.
An experiment on nonlinear laser spectroscopy and magneto-optics at the Advanced Undergraduate Laboratory at Berkeley is described. The experiment consists of three parts. In the first part, students learn to operate a diode laser system and characterize its performance using a Fabry–Perot spectrum analyzer. In the second part, Doppler-broadened laser-induced fluorescence and Doppler-free saturated absorption spectra of the rubidium D2 line (780 nm) are recorded and analyzed. Finally, in the third part of the experiment, which we describe in greater detail, the near-resonant magneto-optical rotation is investigated. Nonlinear light-atom interaction leads to spectacular manifestations of the resonant Faraday effect—polarization plane rotation in a magnetic field applied along the direction of light propagation radically different from the linear case. In particular, narrow (∼30 Hz) effective line widths are observed in this experiment corresponding to a rotation enhancement by some seven orders of magnitude compared to the linear Faraday rotation.
Up to now, Doppler-free nonlinear spectroscopy has been applied to atoms inside a gas medium (volume spectroscopy). We have extended these methods to atoms in the vicinity of a surface. The basic principle consists of monitoring reflectivity changes produced when a laser beam, incident on a glass–vapor interface, is brought into resonance with an atomic transition. For Doppler-free spectroscopy, two counterpropagating beams are used to operate velocity selection. If these two beams are under normal incidence in the glass—velocity selection perpendicular to the surface—one observes saturated dispersion (selective reflection sensitive to the real index). For incidence angles in the glass (prism) larger than the critical angle (total internal reflection), a standing evanescent wave is produced in the gas (velocity selection along the surface), and saturated absorption is detected. Experimental demonstration was performed on the Na resonance line; high sensitivity (10−4 relative reflectivity change) and spectral resolution as good as 20 MHz were obtained. The main limitation to better resolution comes from the short atomic transit time in the evanescent wave (typical extension ~λ). Relevant applications of these techniques should also concern the diagnostics of optically thick media, as analysis of interaction between gas-phase atoms and the surface, notably atom–wall collisions, and modification of the spontaneous emission characteristics.