An analysis is made of the interaction between an alkali metal atom and a strong laser pulse in the presence of a static magnetic field. It is assumed that the carrier frequency of the pulse is close to the frequency of the S1/2–P3/2 transition. It is shown that a weak ellipticity of the polarization of the pulse may give rise to a self-induced adiabatic population inversion. This effect can be studied by measuring the emf associated with a change in the average magnetic moment of an atom. An investigation is made of the dependence of the amplitude and duration of this emf signal on the laser pulse parameters. Changes in the structure of the signal associated with changes in the pulse frequency are discussed.An analysis is made of the interaction between an alkali metal atom and a strong laser pulse in the presence of a static magnetic field. It is assumed that the carrier frequency of the pulse is close to the frequency of the S1/2–P3/2 transition. It is shown that a weak ellipticity of the polarization of the pulse may give rise to a self-induced adiabatic population inversion. This effect can be studied by measuring the emf associated with a change in the average magnetic moment of an atom. An investigation is made of the dependence of the amplitude and duration of this emf signal on the laser pulse parameters. Changes in the structure of the signal associated with changes in the pulse frequency are discussed.

Soviet Journal of Quantum ElectronicsJul 31, 19851 citation

Lasers without population inversion

O. A. Kocharovskaia, Paul Mandel, Ia. I. Khanin

Известия Российской академии наук Физика атмосферы и океанаJan 1, 19905 citations

Stimulated emission of 0.2-THz phonons in La F3 : Er3+

D. J. Sox, John E. Rives, Richard S. Meltzer

Stimulated emission of phonons in the 0.2-THz frequency range is observed in La ${\mathrm{F}}_{3}$ : ${\mathrm{Er}}^{3+}$ . The phonons are generated in the relaxation between the Kramers components of the $^{4}S_{\frac{3}{2}}(1)$ state of ${\mathrm{Er}}^{3+}$ split in a magnetic field after inverting the population with a pulsed tunable dye laser. The stimulated emission is identified from the temporal behavior of the luminescence from the upper Kramers component which shows a speedup in the relaxation during inversion. The population dynamics are analyzed with the rate equations for the system. Comparison with experiment indicates strong preferential stimulated emission along the axis of the cylindrically excited volume and a gain of up to 5 ${\mathrm{mm}}^{\ensuremath{-}1}$. The population inversion exists sufficiently long for phonon propagation over macroscopic distances and the phonon frequency is tunable with the magnetic field.Stimulated emission of phonons in the 0.2-THz frequency range is observed in La${\mathrm{F}}_{3}$:${\mathrm{Er}}^{3+}$. The phonons are generated in the relaxation between the Kramers components of the $^{4}S_{\frac{3}{2}}(1)$ state of ${\mathrm{Er}}^{3+}$ split in a magnetic field after inverting the population with a pulsed tunable dye laser. The stimulated emission is identified from the temporal behavior of the luminescence from the upper Kramers component which shows a speedup in the relaxation during inversion. The population dynamics are analyzed with the rate equations for the system. Comparison with experiment indicates strong preferential stimulated emission along the axis of the cylindrically excited volume and a gain of up to 5 ${\mathrm{mm}}^{\ensuremath{-}1}$. The population inversion exists sufficiently long for phonon propagation over macroscopic distances and the phonon frequency is tunable with the magnetic field.

Physical review. B, Condensed matterApr 15, 198218 citations

Influence of Magnetic Field on Amplification without Inversion Induced by a Femtosecond Pulse Train

Qianqian Ji, Rui Ma, Tianwei Jiang +1 more

Taking advantage of the short pulse duration and the high repetition rate of the fs pulse train, amplification without inversion (AWI) can be achieved in two- or three-level atomic systems. A modulation method using a static magnetic field to control such AWI gain in an atomic system is proposed. The schematic model of the 52S1/2−52P1/2 transition of 87Rb is adopted, and the results show that the system gain can be significantly enhanced and modulated by the magnetic field, while the population inversion can be almost completely suppressed. Moreover, the pulse number, pulse repetition period, and pulse area can also be utilized to modulate the AWI gain.Taking advantage of the short pulse duration and the high repetition rate of the fs pulse train, amplification without inversion (AWI) can be achieved in two- or three-level atomic systems. A modulation method using a static magnetic field to control such AWI gain in an atomic system is proposed. The schematic model of the 52S1/2−52P1/2 transition of 87Rb is adopted, and the results show that the system gain can be significantly enhanced and modulated by the magnetic field, while the population inversion can be almost completely suppressed. Moreover, the pulse number, pulse repetition period, and pulse area can also be utilized to modulate the AWI gain.

Applied SciencesFeb 9, 20220 citations

Nonadiabatic population inversion by laser frequency switching

A. Turrin

Physics Letters ASep 1, 19781 citation

Stimulated emission of phonons in the 0.2-THz frequency range is observed in La

{\mathrm{F}}_{3}

{\mathrm{Er}}^{3+}

. The phonons are generated in the relaxation between the Kramers components of the

^{4}S_{\frac{3}{2}}(1)

state of

{\mathrm{Er}}^{3+}

split in a magnetic field after inverting the population with a pulsed tunable dye laser. The stimulated emission is identified from the temporal behavior of the luminescence from the upper Kramers component which shows a speedup in the relaxation during inversion. The population dynamics are analyzed with the rate equations for the system. Comparison with experiment indicates strong preferential stimulated emission along the axis of the cylindrically excited volume and a gain of up to 5 ${\mathrm{mm}}^{\ensuremath{-}1}$. The population inversion exists sufficiently long for phonon propagation over macroscopic distances and the phonon frequency is tunable with the magnetic field.