title: Quantum focusing and coherent control of nonresonant two-photon absorption in frequency domain.
abstract: We theoretically investigate the nonresonant two-photon absorption (TPA) process in a two-level atom induced by a weak chirped pulse in the frequency domain. According to the extremum condition of the two-photon transition probability (TPTP) at the transition center frequency, we propose a Fresnel-inspired pulse tailoring scheme for TPA that is significantly different from that of Broers et al. [Phys. Rev. A46, 2749 (1992)]. Using this scheme, the TPTP can be focused or eliminated completely by constructively or destructively modulating various pathways of the quantum interference. Our results are a significant improvement on those obtained by Broers et al. and will have potential applications in selective two-photon microscopy and spectroscopy.
authors: Baihong
authors: B
authors: Li
authors: Yonggang
authors: Y
authors: Xu
authors: Lan
authors: L
authors: An
authors: Qianlan
authors: Q
authors: Lin
authors: Haifei
authors: H
authors: Zhu
authors: Fukun
authors: F
authors: Lin
authors: Yongfang
authors: Y
authors: Li