Ultrafast quantum path interferometry using phase-locked femtosecond pulses

Krishna Rai Dastidar

D. A. Wiersma, Wim P. de Boeij, M. Emde +1 more

Kazutaka G. Nakamura, Kensuke Yokota, Yuki Okuda +5 more

Ultrafast quantum-path interferometry by using a pair of relative-phase-locked femtosecond pulses is proposed to evaluate the contribution of each quantum path in an optical transition. The observed characteristic interference fringes (collapse and revival) reveal that the impulsive stimulated Raman scattering is dominant in the coherent-phonon generation in $n$-type GaAs even in an opaque condition. It is demonstrated that the optical dual-pulse pumping actively creates quantum mechanical superposition of the electronic and phononic states in a bulk solid.

Juan F. Hodelin

Durrani, Ijaz

Hidetaka Yamada, Keiichi Yokoyama, Y. Teranishi +10 more

A demonstration of coherent quantum control for ultrafast precise selection of closely-lying states is reported. A phase-locked pair of femtosecond laser pulses is generated through a pulse shaper to excite the ground-state cesium atom to the $\mathrm{Cs}(7{D}_{3∕2})$ and $\mathrm{Cs}(7{D}_{5∕2})$ states by two-photon absorption. The excited state population is measured by detecting fluorescence from each spin-orbit state. By controlling the phase-difference of the pulse pair, an ultrafast precise selection is accomplished. The contrast ratio of the maximal to minimal selection ratio exceeds ${10}^{3}$ with the delay less than $400\phantom{\rule{0.3em}{0ex}}\mathrm{fs}$.