Effect of resonance radiative processes on the amplification factor

Popova, T. Ya.; Popov, A. K.

doi:10.1007/bf00609204

Cited by 13 publications

(9 citation statements)

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“…This was emphasized in [24,27] (see also [22,23,30,36]). Optimum conditions for the inversionless amplification in a uniformly broadened three-level system were analyzed in [28][29][30] in detail. The refraction index at frequency ω 2 is defined as Im(−iG * 2 r 2 ) and, generally, the laser-induced minimum (including zero) absorption can coincide with the resonant refraction index maximum [11,40].…”

Section: Laser-induced Intra-atomic Coherence and Classification Of Rmentioning

confidence: 99%

“…The refraction index at frequency ω 2 is defined as Im(−iG * 2 r 2 ) and, generally, the laser-induced minimum (including zero) absorption can coincide with the resonant refraction index maximum [11,40]. As is emphasized in [22][23][24][25][26][27][28][29][30]36], the splitting effect and the NIE as a whole, varying the spectral line shape and causing the difference in pure emission (spontaneous or induced) and absorption spectra, does not vary its integral intensity, which is defined only by saturation effects,…”

Section: Laser-induced Intra-atomic Coherence and Classification Of Rmentioning

confidence: 99%

“…There is an optimum relationship between the initial population differences ∆n 4 and ∆n 3 , created by an additional noncoherent excitation. Optimum conditions for the inversionless amplification and transparency for opened and closed systems are analyzed in [28][29][30] in more detail.…”

Section: Inversionless Amplification Of the Probing Wavementioning

confidence: 99%

“…Thus, we separate the V -shaped three-level configuration g − n − m. The strong field E 3 at frequency Ω 3 couples the levels m and n. The weak field at frequency ω 2 probes the transition gn. Using (3) and (4) we derive the absorption α 2 and refraction n 2 indices at frequency ω 2 , (see also [28][29][30]),…”

Section: Inversionless Amplification and Resonantly Amplified Refractmentioning

confidence: 99%

“…These results are generalized in monographs [4, 15-18, 22, 23, 30, 33, 36]. In [25,28,29,30] the possible inversionless amplification was analyzed for three-level systems at the discrete optical transitions. Corresponding experimental studies were carried out in [21,33,34].…”

Section: Introductionmentioning

confidence: 99%

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Попов

Martynov

2002

Biology Bulletin of the Russian Academy of Sciences

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The effects of coherence of quantum transitions and the interference of resonant nonlinear optical processes on the spectra of absorption, amplification, and nonlinear-optical generation are considered. The most favorable conditions are discussed for the inversionless amplification, resonant refraction in the absence of absorption and for resonant enhancement of nonlinear-optical generation at the discrete transitions and the transitions to continuum.

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Section: Laser-induced Intra-atomic Coherence and Classification Of Rmentioning

confidence: 99%

Section: Laser-induced Intra-atomic Coherence and Classification Of Rmentioning

confidence: 99%

Section: Inversionless Amplification Of the Probing Wavementioning

confidence: 99%

Section: Inversionless Amplification and Resonantly Amplified Refractmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Попов

Martynov

2002

Biology Bulletin of the Russian Academy of Sciences

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Lasing without inversion: A useful concept?

Mandel

1993

Contemporary Physics

136

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Optical switching and inversionless amplification controlled by state-dependent alignment of molecules

Popov¹,

Slabko²

2005

J. Phys. B: At. Mol. Opt. Phys.

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We propose a method to achieve amplification without population inversion by anisotropic molecules whose orientation by an external electric field is state-dependent. It is based on decoupling of the lower-state molecules from the resonant light while the excited ones remain emitting. The suitable class of molecules is discussed, the equation for the gain factor is derived, and the magnitude of the inversionless amplification is estimated for the typical experimental conditions. Such switching of the sample from absorbing to amplifying via transparent state is shown to be possible both with the aid of dc and ac control electric fields.PACS numbers: 42.70.Hj Amplification of light is determined by the difference between the net absorbtion and stimulated emission of radiation. Usually, this requires larger population of the upper quantum state then the lower one that are coupled by the induced transitions. However, the amount of absorbed and emitted photons depend not only on the populations of the resonant energy levels but also on the probabilities of the induced transitions and on distribution of the populations over the energy-degenerated states. Therefore, the inversion of population is, generally speaking, only a special case, in which the amount of the emitted light prevails over the absorbed one. Based on this fact, a variety of realizations of amplification without population inversion (AWI) was proposed in the early years of quantum electronics. Such possibility based on a possible difference in velocity distribution in upper and lower states was discussed in [1]. Nonreciprocity of probabilities of induced emission and absorbtion caused by nonlinear interference affect in the field of the auxiliary radiation was investigated for two-level atoms in [2] and for three-level systems in [3]. Corresponding AWI at transitions of neon was predicted and analyzed in details in [4] and proved in the experiments [5]. The asymmetry in the lineshape of net emission and absorption at the transitions to the autoionizing states and related possibility of AWI was considered in [6]. A possible AWI in dichroic molecules was pointed out in [7]. The feasibility of AWI of short pulses in three-level system was considered in [8]. A review of later publications on AWI is given in [9]. An asymmetry in absorption and emission lineshape of two-level system caused by its interaction with a thermostat is discussed in recent publication [10]. In this paper we propose and discuss a method of achieving lasing without population inversion by the anisotropic molecules. It bases on selective alignment and consequent decoupling the lower-state molecules from the polarized resonant radiation, while the upper-state molecules remain amplifying this radiation through its stimulated emission.In electrodipole approximation, the probability of induced transitions between levels m and g, W mg , depends on the factor d mg cos θ, which is the projection of the electrodipole transition matrix element on a direction of a vector of a resonant oscill...

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Effect of resonance radiative processes on the amplification factor

Cited by 13 publications

References 1 publication

Untitled

Untitled

Lasing without inversion: A useful concept?

Optical switching and inversionless amplification controlled by state-dependent alignment of molecules

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