Narrow Resonances Induced in an Absorbing Gas by an Intense Light Field

Near-resonant four-wave light mixing in Na vapor with inert buffer gases reveals collision-induced coherences when the difference frequency between two incident light beams equals the hyperfine splitting or the Zeeman splitting between two states of the $3^{2}S$ ground-state manifold. The Doppler broadening of the corresponding resonances decreases with increasing buffer-gas pressure. The width of the resonances becomes significantly narrower than the spontaneous linewidth of the near-resonant intermediate state and is determined by spin-exchange collisions between ground-state atoms. The dependence of the intensity of these collision-induced resonances on buffer-gas pressure and detuning from one-photon resonances is measured. Selection rules for various polarizations of the incident light fields and directions of an externally applied magnetic field are established.Near-resonant four-wave light mixing in Na vapor with inert buffer gases reveals collision-induced coherences when the difference frequency between two incident light beams equals the hyperfine splitting or the Zeeman splitting between two states of the $3^{2}S$ ground-state manifold. The Doppler broadening of the corresponding resonances decreases with increasing buffer-gas pressure. The width of the resonances becomes significantly narrower than the spontaneous linewidth of the near-resonant intermediate state and is determined by spin-exchange collisions between ground-state atoms. The dependence of the intensity of these collision-induced resonances on buffer-gas pressure and detuning from one-photon resonances is measured. Selection rules for various polarizations of the incident light fields and directions of an externally applied magnetic field are established.

Physical Review AAug 1, 198490 citations

New nonlinear resonances in a gas in the presence of a strong optical field

E. V. Baklanov, Veniamin P. Chebotayev, M. P. Staroselsky

Applied Physics BAug 1, 19892 citations

Light effects in the atomic-motion-induced Ramsey narrowing of dark resonances in wall-coated cells

Evelina Breschi, Georgy A. Kazakov, C. Schori +4 more

We report on light shift and broadening in the atomic-motion-induced Ramsey narrowing of dark resonances prepared in alkali-metal vapors contained in wall-coated cells without buffer gas. The atomic-motion-induced Ramsey narrowing is due to the free motion of the polarized atomic spins in and out of the optical interaction region before spin relaxation. As a consequence of this effect, we observe a narrowing of the dark resonance linewidth as well as a reduction of the ground states' light shift when the volume of the interaction region decreases at constant optical intensity. The results can be intuitively interpreted as a dilution of the intensity effect similar to a pulsed interrogation due to the atomic motion. Finally the influence of this effect on the performance of compact atomic clocks is discussed.We report on light shift and broadening in the atomic-motion-induced Ramsey narrowing of dark resonances prepared in alkali-metal vapors contained in wall-coated cells without buffer gas. The atomic-motion-induced Ramsey narrowing is due to the free motion of the polarized atomic spins in and out of the optical interaction region before spin relaxation. As a consequence of this effect, we observe a narrowing of the dark resonance linewidth as well as a reduction of the ground states' light shift when the volume of the interaction region decreases at constant optical intensity. The results can be intuitively interpreted as a dilution of the intensity effect similar to a pulsed interrogation due to the atomic motion. Finally the influence of this effect on the performance of compact atomic clocks is discussed.

Physical Review ADec 7, 201044 citations

Nonlinear spectroscopy within a Doppler profile based on "competitive" resonances

Vladilen S Letokhov, B. D. Pavlik

An analysis is made of the width and resolution of power resonances in a ring gas laser with a nonlinearly absorbing cell in the resonator. It is shown that in the case of the Lorentzian profile of an inverted Lamb dip in a nonlinearly absorbing cell the resolution of competitive resonances is equal to the homogeneous linewidth in spite of the fact that the width of competitive resonances is much smaller than the homogeneous width (Lamb dip width). An analysis is made of the narrowing of the tip of the Lamb dip in the case of long-lived molecular levels and particularly of the field broadening of the narrowed tip. It is found that the resolution of competitive resonances in the case of a narrowed tip of a Lamb dip in a low-pressure gas cell may be much higher than the resolution governed by the time needed to cross a light beam by molecules with an average thermal velocity.An analysis is made of the width and resolution of power resonances in a ring gas laser with a nonlinearly absorbing cell in the resonator. It is shown that in the case of the Lorentzian profile of an inverted Lamb dip in a nonlinearly absorbing cell the resolution of competitive resonances is equal to the homogeneous linewidth in spite of the fact that the width of competitive resonances is much smaller than the homogeneous width (Lamb dip width). An analysis is made of the narrowing of the tip of the Lamb dip in the case of long-lived molecular levels and particularly of the field broadening of the narrowed tip. It is found that the resolution of competitive resonances in the case of a narrowed tip of a Lamb dip in a low-pressure gas cell may be much higher than the resolution governed by the time needed to cross a light beam by molecules with an average thermal velocity.

Soviet Journal of Quantum ElectronicsNov 30, 19750 citations

Spatial Effects in Saturation of Resonance Absorption of a Gas in a Light Field

Vladilen S Letokhov

Journal of Experimental and Theoretical PhysicsJan 1, 19690 citations

3^{2}S

ground-state manifold. The Doppler broadening of the corresponding resonances decreases with increasing buffer-gas pressure. The width of the resonances becomes significantly narrower than the spontaneous linewidth of the near-resonant intermediate state and is determined by spin-exchange collisions between ground-state atoms. The dependence of the intensity of these collision-induced resonances on buffer-gas pressure and detuning from one-photon resonances is measured. Selection rules for various polarizations of the incident light fields and directions of an externally applied magnetic field are established.