engleski

Coherent population dynamics in rubidium atoms excited by resonant 0π pulses

We investigate the time dynamics of a four-level rubidium atomic system excited by a train of 0π pulses. Resonant 0π pulse shaping is achieved by propagation of weak femtosecond (fs) pulses through rubidium vapor and characterized using frequency resolved optical gating and within the linear dispersion theory. The excitation of the Rb atoms by 0π pulse train is studied experimentally by modified direct frequency comb spectroscopy and theoretically within the density-matrix approach. We show that accumulation of populations and coherences, as typical pulse train excitation effects, strongly depend upon the strength of the resonant 0π pulse shaping. Stronger pulse shaping reduces the coherent accumulation effects, eventually leading to the disappearance of the velocity selective optical pumping observed in the frequency domain.

resonant 0π pulse shaping; coherent control; frequency comb spectroscopy

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