In this paper, we investigated the coherent degenerate and nondegenerate four-wave interaction in the propagation of a femtosecond laser pulse in atomic rubidium vapor. In the case of degenerate four-wave interaction, the mechanism for optical switching in an optically dense resonant medium is considered. The third-order nonlinear interaction of the laser beams intersecting in the cell at a small angle leads to a nonlinear response in the form of a fourth beam, which occurs as a result of the interaction between the two pump beams and the third signal laser beam.In this paper, we investigated the coherent degenerate and nondegenerate four-wave interaction in the propagation of a femtosecond laser pulse in atomic rubidium vapor. In the case of degenerate four-wave interaction, the mechanism for optical switching in an optically dense resonant medium is considered. The third-order nonlinear interaction of the laser beams intersecting in the cell at a small angle leads to a nonlinear response in the form of a fourth beam, which occurs as a result of the interaction between the two pump beams and the third signal laser beam.

Russian Journal of Physical Chemistry BJul 1, 20150 citations

Cancellation of the coherent accumulation in rubidium atoms excited by a train of femtosecond pulses

Ticijana Ban, Damir Aumiler, Hrvoje Skenderović +3 more

Springer series in chemical physicsJan 1, 20095 citations

Cone emission induced by femtosecond excitation in rubidium vapor

Hrvoje Skenderović, Ticijana Ban, Nataša Vujičić +3 more

We studied the emission from dense rubidium vapor under 100-fs pulsed laser excitation in the 730--820 nm range. Self-focusing along with a conical emission (CE) was observed for the excitation in the blue wing of $D2$ atomic resonance. Self-defocusing occurred for the red-wing excitation. This is in accordance with the theory of the intensity dependent nonlinear refraction index. In the case of the CE observation, our experimental results are attributed to the self-phase modulation of the laser beam interacting with the near-resonant atomic medium.We studied the emission from dense rubidium vapor under 100-fs pulsed laser excitation in the 730--820 nm range. Self-focusing along with a conical emission (CE) was observed for the excitation in the blue wing of $D2$ atomic resonance. Self-defocusing occurred for the red-wing excitation. This is in accordance with the theory of the intensity dependent nonlinear refraction index. In the case of the CE observation, our experimental results are attributed to the self-phase modulation of the laser beam interacting with the near-resonant atomic medium.

Physical Review AJun 11, 200811 citations

Interaction of Phase-Modulated Femtosecond Pulses with an Optically Dense Quasi-Resonant Medium of Rubidium Vapors

Sergei N Bagaev, A. A. Preobrazhenskaya, Nikolai A. Timofeev +7 more

Abstract For the first time, it is demonstrated that the magnitude and sign of the effect of “spectral condensation” of a laser pulse at the resonant-transition frequency of a dense medium can be controlled by changing the driving-pulse parameters (chirp, pulse width, and pulse amplitude). In the process of this, importantly, the driving-pulse energy and spectrum remain unchanged. Direct time-resolved measurements revealed an oscillatory character of the induced superradiance of rubidium vapors representing a long train of decaying short pulses. The width and repetition rate of the pulses in the train are determined by atomic density N0 of the medium, while the width of an entire superradiance pulse (10 ps) is considerably larger than that of the driving laser pulse (50 fs).Abstract For the first time, it is demonstrated that the magnitude and sign of the effect of “spectral condensation” of a laser pulse at the resonant-transition frequency of a dense medium can be controlled by changing the driving-pulse parameters (chirp, pulse width, and pulse amplitude). In the process of this, importantly, the driving-pulse energy and spectrum remain unchanged. Direct time-resolved measurements revealed an oscillatory character of the induced superradiance of rubidium vapors representing a long train of decaying short pulses. The width and repetition rate of the pulses in the train are determined by atomic density N0 of the medium, while the width of an entire superradiance pulse (10 ps) is considerably larger than that of the driving laser pulse (50 fs).

Optics and SpectroscopyNov 1, 20182 citations

D2

atomic resonance. Self-defocusing occurred for the red-wing excitation. This is in accordance with the theory of the intensity dependent nonlinear refraction index. In the case of the CE observation, our experimental results are attributed to the self-phase modulation of the laser beam interacting with the near-resonant atomic medium.