A laser-excited three-level atom. II numerical results

Numerical calculations are presented for the interference spectra of a laser-excited three-level atom, where the strong and the weak atomic transitions are driven by resonant and nonresonant laser fields, respectively. The spectral functions describing the interference spectra for the electric dipole allowed excited state have been considered in the low- and high-intensity limit of the laser field operating in the strong transition. The interference spectra arise from the competition between short-lifetime spontaneous processes and short- and long-lifetime excitations induced by the strong and the weak laser fields, respectively. Both laser fields have been treated as quantized and as classical entities. The computed spectra have been presented graphically for different values of the Rabi frequencies and detunings of the weak laser field. It is shown that the decrease in the intensity of the short-lifetime excitation may provide a measure of the spectral width of the long-lifetime excitation.

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A laser-excited three-level atom

Canadian Journal of Physics ◽

10.1139/p90-051 ◽

1990 ◽

Vol 68 (3) ◽

pp. 321-333 ◽

Cited By ~ 5

Author(s):

Constantine Mavroyannis

Keyword(s):

Excited States ◽

Laser Field ◽

Excitation Spectra ◽

Spectral Functions ◽

Laser Fields ◽

At Resonance ◽

Level Atom ◽

Short Lifetime ◽

Strong Transition ◽

Long Lifetime

We considered the excitation spectra for the excited states of a three-level atom, where the strong and the weak atomic transitions are driven by resonant and nonresonant laser fields, respectively. The spectral functions describing the excitation spectra for the electric dipole allowed excited state and for the metastable state of the atom have been derived when both laser fields are quantized as well as when they are treated as classical entities. In the low-intensity limit of the laser field operating in the strong transition, there are two short-lifetime excitations, the spontaneous one and the induced one, which appear at the same frequency, and a long-lifetime excitation induced by the weak laser field. These excitations compete with each other at resonance as well as at finite detunings of the weak laser field. In the high-intensity limit of the laser field operating in the strong transition, the competition is between the short- and the long-lifetime side bands, which are induced by the strong and the weak laser fields, respectively. The ratio of the maximum intensities of the peaks describing the long- and the short-lifetime excitations exhibits a resonance variation with the detuning of the weak laser field. Comparison between the results obtained when the laser fields are treated as quantized and as classical entities is made.

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Interference spectra in a two-level atom

Canadian Journal of Physics ◽

10.1139/p90-199 ◽

1990 ◽

Vol 68 (12) ◽

pp. 1389-1395 ◽

Cited By ~ 6

Author(s):

Constantine Mavroyannis

Keyword(s):

Excited State ◽

High Intensity ◽

Laser Field ◽

Stark Effect ◽

Ground States ◽

Spectral Functions ◽

Laser Photon ◽

Level Atom ◽

Dynamic Stark Effect ◽

Two Peaks

We have considered the interference spectra arising from the competition between a spontaneous process and one induced by a laser field in a two-level atom. Expressions for the spectral functions have been derived describing the spectra of the excited and ground states of the atom in the low- and high-intensity limit of the laser field. For the excited-state spectra in the low-intensity limit, the frequency profiles of the two peaks, which arise from the spontaneous and the induced processes, cancel each other out completely near the center of the line, while for the ground state the induced process dominates. For finite values of the detuning, the spectra of the excited state consist of two peaks, which have positive and negative frequency profiles, respectively. The computed spectra have been graphically presented and discussed. In the high-intensity limit, the dynamic Stark effect dominates the spectra of the excited and ground states of the atom. Expressions for the correlation functions have been derived that describe the emission or the absorption of a laser photon at two different times. The derived expressions for the corresponding delay functions in the low- and high-intensity limits have been found to be identical to those recently proposed in the literature. The laser field has been treated as a classical as well as a quantized entity.

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Induced absorption and stimulated emission in a driven two-level atom

Canadian Journal of Physics ◽

10.1139/p92-072 ◽

1992 ◽

Vol 70 (6) ◽

pp. 427-431 ◽

Cited By ~ 2

Author(s):

Constantine Mavroyannis

Keyword(s):

Excited State ◽

Ground State ◽

Laser Field ◽

Low Frequency ◽

Ultrashort Pulses ◽

Stimulated Emission ◽

Spectral Lines ◽

Laser Photon ◽

Induced Absorption ◽

Level Atom

We have considered the induced processes that occur in a driven two-level atom, where a laser photon is absorbed and emitted by the ground and by the excited states of the atom, respectively. In the low-intensity limit of the laser field, the induced spectra arising when a laser photon is absorbed by the ground state of the atom consist of two peaks describing induced-absorption and stimulated-emission processes, respectively, where the former prevails over the latter. Asymmetry of the spectral lines occurs at off-resonance and its extent depends on the detuning of the laser field. The physical, process where a laser photon is emitted by the excited state is the reverse of that arising from the absorption of a laser photon by the ground state of the atom. The former differs from the latter in that the emission of a laser photon by the excited state occurs in the low-frequency regime and that the stimulated-emission process prevails over that of the induced absorption. In this case, amplification of ultrashort pulses is likely to occur without the need of population inversion between the optical transitions. The computed spectra are graphically presented and discussed.

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Optical mixing of frequencies of a strong bichromatic field interacting with a three-level atom. II. Numerical results

Canadian Journal of Physics ◽

10.1139/p82-030 ◽

1982 ◽

Vol 60 (2) ◽

pp. 245-251 ◽

Cited By ~ 14

Author(s):

Constantine Mavroyannis ◽

K. J. Woloschuk ◽

D. A. Hutchinson ◽

Christine Downie

Keyword(s):

Ground State ◽

Laser Field ◽

Excitation Spectra ◽

Laser Fields ◽

Level Atom ◽

Reduced Frequency ◽

Spontaneous Emission Probability ◽

Bichromatic Field ◽

Optical Mixing ◽

Selection Of

We have numerically calculated the excitation spectra arising from the 3rd order mixing of the frequencies ωa and ωb of two laser fields interacting with a three-level atom, where each laser field resonantly couples the ground state with each excited state of the atom, respectively. In the limit of high photon densities, the excitation spectra near the reduced frequency X = (ω−ωa + 2ωb)/γ0 ≈ 0 are considered as a function of the reduced Rabi frequencies ηa and ηb of the two laser fields, respectively and γ0 is the spontaneous emission probability. For ηa < ηb the spectra consist of a doublet peaked at [Formula: see text] and its intensity is constant. When ηa = ηb, the spectra are composed of five pairs of bands peaked at [Formula: see text], and [Formula: see text]. When ηa < ηb the computed spectra consist of five pairs of bands, where the intensities of the peaks at [Formula: see text] and [Formula: see text] are positive indicating absorption, those at [Formula: see text] are negative implying amplification, and the two pairs of peaks at [Formula: see text] have positive and negative components describing the mixed process of absorption–amplification. The intensities of these bands are found to vary as (ηa/ηb)2 for (ηa/ηb) > 1 and, therefore, the intensities of the bands are immensely enhanced as the value of the ratio (ηa/ηb) increases. The computed spectra for a wide selection of Rabi frequencies are graphically presented and compared with those derived by analytical methods.

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RESONANCE FLUORESCENCE THEORY ANALYZED BY SUPERSYMMETRIC TRANSFORMATION

Modern Physics Letters B ◽

10.1142/s021798490000015x ◽

2000 ◽

Vol 14 (03) ◽

pp. 95-102 ◽

Cited By ~ 2

Author(s):

HONG-YI FAN ◽

XIAN-TING LIANG

Keyword(s):

Laser Field ◽

Single Mode ◽

Resonance Fluorescence ◽

Physical Processes ◽

Laser Fields ◽

Strong Laser Field ◽

Mode Laser ◽

Single Mode Laser ◽

Strong Laser ◽

Level Atom

In this paper, use is made of supersymmetric transformation to discuss resonance fluorescence of two-level atom driven by a strong laser field and that of three-level atom driven by two single-mode laser fields. The supersymmetric derivation makes the analysis of the physical processes more accurate, clear and efficient. As a result, some new physical processes are revealed by this method.

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Nonperturbative generation of above-threshold harmonics from pre-excited argon atoms in intense mid-infrared laser fields

High Power Laser Science and Engineering ◽

10.1017/hpl.2017.26 ◽

2017 ◽

Vol 5 ◽

Cited By ~ 2

Author(s):

Guihua Li ◽

Hongqiang Xie ◽

Ziting Li ◽

Jinping Yao ◽

Wei Chu ◽

...

Keyword(s):

Excited State ◽

Femtosecond Laser ◽

Pulse Energy ◽

Laser Pulses ◽

Infrared Laser ◽

Femtosecond Laser Pulses ◽

Probe Laser ◽

Laser Fields ◽

Mid Infrared ◽

Highly Nonlinear

We experimentally investigate the generation of above-threshold harmonics completely from argon atoms on an excited state using mid-infrared femtosecond laser pulses. The highly nonlinear dependences of the observed signal on the pulse energy and polarization of the probe laser pulses indicate its nonperturbative characteristic.

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