Quantum dynamics of molecular multiphoton excitation in intense laser and static electric fields: Floquet theory, quasienergy spectra, and application to the HF molecule

Abstract

Articles you may be interested inClassical and quantum mechanical studies of overtone and multiphoton absorption of HF in an intense laser field J. Chem. Phys. 80, 4738 (1984) The multiphoton excitation dynamics of vibration-rotation states in diatomic molecules in intense laser and static electric fields is investigated. The Floquet matrix method is used to calculate the quasienergy and multiphoton absorption spectra of the HF molecule as functions of field strengths and frequency. Nonlinear effects such as power broadening. dynamic Stark shift. Auder-Townes multiplet splitting. hole burning. and S -hump behaviors. etc .• are observed and discussed in terms of quasienergy diagrams. Many of the salient features in the spectral line shapes may be qualitatively understood in terms of an analytical three-level model. The addition of a dc electric field removes the restriction of the rotational dipole selection rule and causes significant intermixing of the bare molecular vibrator states. Due to the greater number of strongly coupled nearby states in the dc field. nonlinear effects sqch as those mentioned above appear at a much lower ac field strength than they would in the absence of the dc field. The introduction. of an external dc field, therefore, strongly enhances the multiphoton excitation probabilities and results in a much, richer spectrum.

Vibrational excitation of CO molecule in collision with He atom in the presence of an IR laser beam

“…where YXr) and YJ(r) are the Morse oscillator wave functions. Substituting eqs (15), (17), and ( 18) into ( 14) and making use of the standard integral [26] exp [-a…”

Multiphoton rovibrational excitation of diatomic molecules in the presence of an intense infrared laser beam using a non-perturbative quasi-energy technique

“…In the past many workers have studied the collisionless multiphoton excitation (MPE) and dissociation (MPD) of molecules in the presence of an infrared laser field (Bloembergen and Yablonovich 1978, Schulz et al 1979, Chu 1985, Jolicard and Billing 1986, Mohan and Snarma i986, Siarma et ai i988j. Tine semiciassicai Fioquet theory has been quite successful for non-perturbative treatment of the MPE of some simple systems (Moloney and Faisal 1979a, b, Leasure et al 1981, Chu et al 1982, Sharma et al 1988. However because of the large dimension of the Floquet matrix (the Floquet matrix is truncated to a N x N matrix with N = N , x N , x N,, where N , is the number of photon blocks, N , is the number of vibrational states and N , is the number of rotational states), the Floquet analysis becomes very expansive in terms of computer time even for some simple systems.…”