The free induction decay (FID) after saturation by a laser radiation pulse of finite duration is studied for systems with spectral diffusion. The exact solutions of the FID signal shape have been obtained in the framework of telegraph noise model as well as model of noncorrelated spectral exchange. These solutions take into account the finite duration of saturating field and are valid at arbitrary value of the spectral exchange rate and the amplitude of the coherent field. A selfconsistent explanation of the field dependence of the FID rate found by Szabo and Muramoto is obtained under the slow noncorrelated spectral diffusion.The free induction decay (FID) after saturation by a laser radiation pulse of finite duration is studied for systems with spectral diffusion. The exact solutions of the FID signal shape have been obtained in the framework of telegraph noise model as well as model of noncorrelated spectral exchange. These solutions take into account the finite duration of saturating field and are valid at arbitrary value of the spectral exchange rate and the amplitude of the coherent field. A selfconsistent explanation of the field dependence of the FID rate found by Szabo and Muramoto is obtained under the slow noncorrelated spectral diffusion.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIEMay 10, 19960 citations

Free-induction decay after a pulse saturation for systems with random telegraph frequency

Vladimir S. Malinovsky

The free-induction decay (FID) after saturation by a laser radiation pulse of finite duration is studied for systems with spectral diffusion. The exact solution of the FID signal shape has been obtained in the framework of the telegraph noise model. This solution takes into account the finite duration of the saturating field and is valid at arbitrary values of the spectral exchange rate and the amplitude of the coherent field. The exact expression of the FID signal is derived in the weak-external-field limit. It is shown that the FID signal suddenly disappears after a time equal to the pulse width. This confirms the validity of the theorem on coherent transients, which has been proved for the Bloch equations [A. Schenzle, N. C. Wong, and R. G. Brewer, Phys. Rev. A 22, 635 (1980)].The free-induction decay (FID) after saturation by a laser radiation pulse of finite duration is studied for systems with spectral diffusion. The exact solution of the FID signal shape has been obtained in the framework of the telegraph noise model. This solution takes into account the finite duration of the saturating field and is valid at arbitrary values of the spectral exchange rate and the amplitude of the coherent field. The exact expression of the FID signal is derived in the weak-external-field limit. It is shown that the FID signal suddenly disappears after a time equal to the pulse width. This confirms the validity of the theorem on coherent transients, which has been proved for the Bloch equations [A. Schenzle, N. C. Wong, and R. G. Brewer, Phys. Rev. A 22, 635 (1980)].

Physical Review ADec 1, 19958 citations

Influence of frequency exchange rate on free induction decay after saturation

Anatoly I. Burshtein, Anatoly A. Zharikov, Vladimir S. Malinovsky

The free induction decay (FID) and light-echo kinetics are calculated under the assumption that a two-level system frequency is a purely discontinuous noncorrelated Markovian process, and its statistical distribution is a bi-Lorentzian contour. The latter assumption is primarily mathematical, but useful. The model allows one to obtain an exact solution of the FID problem, which recovers the results obtained earlier with perturbation theory (the fast modulation limit) as well as the result concerning the slow modulation limit. It is shown that only in the latter case does the field dependence of the FID rate found by De Voe and Brewer [Phys. Rev. Lett. 50, 1269 (1983)] have a self-consistent explanation.The free induction decay (FID) and light-echo kinetics are calculated under the assumption that a two-level system frequency is a purely discontinuous noncorrelated Markovian process, and its statistical distribution is a bi-Lorentzian contour. The latter assumption is primarily mathematical, but useful. The model allows one to obtain an exact solution of the FID problem, which recovers the results obtained earlier with perturbation theory (the fast modulation limit) as well as the result concerning the slow modulation limit. It is shown that only in the latter case does the field dependence of the FID rate found by De Voe and Brewer [Phys. Rev. Lett. 50, 1269 (1983)] have a self-consistent explanation.

Physical Review AFeb 1, 199112 citations

Free-induction decay after saturation in dilute ruby

R. Boscaino, F. M. Gelardi

The after-saturation free-induction-decay (FID) rate of an electron spin transition has been measured in a dilute ruby sample, and a marked departure from the Bloch-like behavior has been found. The similarity with the results obtained recently by Szabo and Muramoto [Phys. Rev. A 39, 3992 (1989)] in the same system but for optical FID points out the close link between the non-Bloch behavior of the FID emission observed in optics and in magnetic-resonance systems. Our results are compared with the theoretical predictions of a statistical theory of the FID emission, but poor agreement is found.The after-saturation free-induction-decay (FID) rate of an electron spin transition has been measured in a dilute ruby sample, and a marked departure from the Bloch-like behavior has been found. The similarity with the results obtained recently by Szabo and Muramoto [Phys. Rev. A 39, 3992 (1989)] in the same system but for optical FID points out the close link between the non-Bloch behavior of the FID emission observed in optics and in magnetic-resonance systems. Our results are compared with the theoretical predictions of a statistical theory of the FID emission, but poor agreement is found.

Physical Review AJan 1, 199216 citations

Experimental spectra of oscillatory free-induction decay

R. Boscaino, F. M. Gelardi

The free-induction decay (FID) signals emitted by a two-level spin system ( ${E}_{1}^{\mathcal{'}}$ centers in glassy silica), coherently prepared by a short pulse of resonant radiation, have been experimentally investigated in the frequency domain. Our results show that, under the same conditions in which FID signals are oscillatory in the time domain, the spectra are characterized by a regular series of emission zeros. A vectorial model accounts for the occurrence of the zeros and for their spectral positions.The free-induction decay (FID) signals emitted by a two-level spin system (${E}_{1}^{\mathcal{'}}$ centers in glassy silica), coherently prepared by a short pulse of resonant radiation, have been experimentally investigated in the frequency domain. Our results show that, under the same conditions in which FID signals are oscillatory in the time domain, the spectra are characterized by a regular series of emission zeros. A vectorial model accounts for the occurrence of the zeros and for their spectral positions.

Physical Review AApr 1, 19876 citations

Free-induction decay in the framework of sudden-modulation theory

Anatoly I. Burshtein, Vladimir S. Malinovsky

Sudden-modulation theory is used for the calculation of stationary saturation and polarization of two-level systems. The randomly fluctuating frequency of the two-level system is assumed to be a noncorrelated, purely discontinuous Markovian process. The stationary probability of field-induced transitions is calculated exactly. It is shown that if the frequency modulation is fast (or if the field is strong enough) the transition probability coincides with that obtained in the framework of perturbation theory when the latter is developed in its integrodifferential non-Markovian version. This probability differs from the kinetic probability calculated by Markovian perturbation theory (with fluctuating frequency) in its corresponding spectral wing shape and in the field dependence of its corresponding resonance width. This field dependence is smoother than that in Markovian theory and stabilizes when the resonance width is not equal to the natural transition width. Nevertheless, in the Lorentzian approximation the free-induction decay rate in the framework of exact (or non-Markovian) theory increases with the field in nearly the same way as that in Markovian theory. Almost the same is true of the field dependence of the free-induction decay amplitude in either theory, provided that the signal correlation before and after the field is switched off is neglected. The conditions are found under which the Lorentzian approximation of the transition probability is valid. These conditions are shown to break down when the theory (in the fast-frequency-modulation limit) leads to agreement with experiments reported by De Voe and Brewer [ Phys. Rev. Lett.50, 1269– 1272 ( 1983)].Sudden-modulation theory is used for the calculation of stationary saturation and polarization of two-level systems. The randomly fluctuating frequency of the two-level system is assumed to be a noncorrelated, purely discontinuous Markovian process. The stationary probability of field-induced transitions is calculated exactly. It is shown that if the frequency modulation is fast (or if the field is strong enough) the transition probability coincides with that obtained in the framework of perturbation theory when the latter is developed in its integrodifferential non-Markovian version. This probability differs from the kinetic probability calculated by Markovian perturbation theory (with fluctuating frequency) in its corresponding spectral wing shape and in the field dependence of its corresponding resonance width. This field dependence is smoother than that in Markovian theory and stabilizes when the resonance width is not equal to the natural transition width. Nevertheless, in the Lorentzian approximation the free-induction decay rate in the framework of exact (or non-Markovian) theory increases with the field in nearly the same way as that in Markovian theory. Almost the same is true of the field dependence of the free-induction decay amplitude in either theory, provided that the signal correlation before and after the field is switched off is neglected. The conditions are found under which the Lorentzian approximation of the transition probability is valid. These conditions are shown to break down when the theory (in the fast-frequency-modulation limit) leads to agreement with experiments reported by De Voe and Brewer [ Phys. Rev. Lett.50, 1269– 1272 ( 1983)].

Journal of the Optical Society of America BMay 1, 199124 citations

The free-induction decay (FID) signals emitted by a two-level spin system (

{E}_{1}^{\mathcal{'}}

centers in glassy silica), coherently prepared by a short pulse of resonant radiation, have been experimentally investigated in the frequency domain. Our results show that, under the same conditions in which FID signals are oscillatory in the time domain, the spectra are characterized by a regular series of emission zeros. A vectorial model accounts for the occurrence of the zeros and for their spectral positions.