Biomedical subjects

Panming Fu

Publications and source records attributed to Panming Fu.

3 recordsLinked to original sources

PubMed2006

Generalized n-photon resonant 2n-wave mixing in an (n+1)-level system with phase-conjugate geometry.

A generalized scheme for phase-conjugate resonant 2n-wave mixing, which has a high efficiency and is easy for phase matching, is proposed. As a new type of coherent laser spectroscopy this approach can be employed for studying highly excited atomic states or states with a high angular momentum. To demonstrate its feasibility we have studied the doubly excited autoionizing Rydberg states of Ba by phase-conjugate six-wave mixing, and have furthermore achieved eight-wave mixing in Na. This method may find wide application in related areas such as coherent transient spectroscopy, Autler-Townes spectroscopy and electromagnetically induced transparency. In particular, it may provide new insights into the nature of highly excited states.

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PubMed2004

Theory of the Kapitza-Dirac diffraction effect.

We treat the Kapitza-Dirac diffraction effect observed recently by Batelaan et al. using a newly developed nonperturbative quantum-field scattering theory. Our theory shows that an electron beam passing perpendicularly through a focused standing light wave can produce diffraction patterns. Our theory predicts (1) the minimum value of the ponderomotive energy is (Planck's over 2 pi omega)(2)/m(e)c(2), (2) the critical laser intensity above which the first pair of electron diffraction peaks will occur, and (3) the existence of sidebands in the electron spectra separated far from the central band by a momentum of several hundred photons. Our theory provides a unified explanation of the experimental results of Bucksbaum et al. and Batelaan et al.

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PubMed2002

Rayleigh-type nondegenerate four-wave mixing: ultrafast measurement and field correlation.

We report on an ultrafast longitudinal time measurement by a nonresonant Rayleigh-type nondegenerate four-wave mixing (NFWM). We investigated the field-correlation effects on Rayleigh-type NFWM by examining the time-delayed dependence of the NFWM spectra. Based on the field-correlation effects, a time-delayed method is proposed to suppress the thermal effect, and ultrafast relaxation time can be measured even in an absorbing medium.

Journal Article↗