Ultrafast nonlinear excitation and optical control of vibrational coherence in solids

Игорь Сергеевич Осадько

Игорь Сергеевич Осадько, S.N. Gladenkova

G. Veshapidze, M. L. Trachy, Hyounguk Jang +2 more

Ultrafast and narrow linewidth lasers are combined to study multiphoton photoassociative ionization (PAI) in a Rb magneto-optical trap. Through the use of time of flight spectroscopy and by varying the parameters of the ultrafast laser, the excitation pathway for PAI was determined. It was found that ${{\mathrm{Rb}}_{2}}^{+}$ is formed, not by direct photoionization, but by sequential excitation of ${\mathrm{Rb}}_{2}$ to an autoionizing state. Determining the excitation and ionization pathway was a necessary first step for future efforts in trying to establish coherent control techniques, first for the efficient production of translationally cold ${\mathrm{Rb}}_{2}$, and then for transferring population to a desired vibrationally cold molecular state.

H. Kalt, Claus F. Klingshirn

Felix T. Eickemeyer, Michael Woerner, Andrew M. Weiner +3 more

Amplitude and phase-controlled midinfrared field transients at a wavelength of 12.5 μm induce resonant intersubband excitations in n-type modulation-doped GaAs/AlGaAs quantum wells. The transmitted electric field transients are directly measured by ultrafast electro-optic sampling. Coherent control of intersubband excitations is demonstrated by applying two phase-locked pulses with variable relative phase. A coherent nonlinear response corresponding to partial Rabi flops of up to 60° in the Bloch sphere is observed with excitation pulses of only 1 pJ energy.

R. Pausch, M. Heid, Tao Chen +2 more

Summary form only given. We report on a coherent control experiment in which high-level vibrationally excited wavepackets are generated in the electronic ground state of a molecule by means of the ultrafast stimulated Raman process and resonance enhanced multiphoton ionization (REMPI) detection.