Multiphoton transition probability can be manipulated by tailoring the ultrashort laser pulses. In this paper, we theoretically and experimentally investigate the influence of the absorption bandwidth and line shape on the coherent control of two-photon transitions in two-level system by manipulating the femtosecond laser pulse with the $\ensuremath{\pi}$ spectral phase step. A coherent feature with a coherent peak and two coherent dips can be achieved if the absorption bandwidth is less than twice of the laser spectral bandwidth. The absorption bandwidth decides the coherent peak or dip intensity, and the absorption line shape affects the symmetry of the two coherent dips.Multiphoton transition probability can be manipulated by tailoring the ultrashort laser pulses. In this paper, we theoretically and experimentally investigate the influence of the absorption bandwidth and line shape on the coherent control of two-photon transitions in two-level system by manipulating the femtosecond laser pulse with the $\ensuremath{\pi}$ spectral phase step. A coherent feature with a coherent peak and two coherent dips can be achieved if the absorption bandwidth is less than twice of the laser spectral bandwidth. The absorption bandwidth decides the coherent peak or dip intensity, and the absorption line shape affects the symmetry of the two coherent dips.

Physical Review AOct 2, 200916 citations

Quantum coherent control of ultrashort laser pulses

Jianying Zhou, Jianhua Zeng, Juntao Li

Chinese Science BulletinMar 1, 20082 citations

Selective transition to the closely-lying states Cs(7D3∕2) and Cs(7D5∕2) by femtosecond laser pulses

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 $400\phantom{\rule{0.3em}{0ex}}\mathrm{fs}$ .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 $400\phantom{\rule{0.3em}{0ex}}\mathrm{fs}$.

Physical Review ADec 6, 20056 citations

Quantum coherent control of two-photon transitions by square phase-modulation

Zhang Shi-An, Zugeng Wang, Zhenrong Sun

A femtosecond laser pulse can be tailored to control the two-photon transitions using the ultra-fast pulse-shaping technique. This paper theoretically and experimentally demonstrates that two-photon transitions in molecular system with broad absorption line can be effectively controlled by square phase-modulation in frequency domain, and the influence of all parameters characterizing the square phase-modulation on two-photon transitions is systemically investigated and discussed. The obtained results have potential application in nonlinear spectroscopy and molecular physics.A femtosecond laser pulse can be tailored to control the two-photon transitions using the ultra-fast pulse-shaping technique. This paper theoretically and experimentally demonstrates that two-photon transitions in molecular system with broad absorption line can be effectively controlled by square phase-modulation in frequency domain, and the influence of all parameters characterizing the square phase-modulation on two-photon transitions is systemically investigated and discussed. The obtained results have potential application in nonlinear spectroscopy and molecular physics.

Chinese Physics BAug 1, 20087 citations

\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}