Resonant interactions of diatomic molecules with intense laser fields: time-independent multi-channel Green function theory and application to experiment
Ai. Pegarkov, Resonant interactions of diatomic molecules with intense laser fields: time-independent multi-channel Green function theory and application to experiment, PHYS REPORT, 336(4-5), 2000, pp. 256-411
The resonant interactions of diatomic molecules with UV and VUV intense las
er radiation are investigated within an original non-perturbative approach
of multi-channel nuclear wave functions and Green's functions. The interact
ions are considered in a quantum-electrodynamic picture where the laser fie
ld and molecule are treated as quantum objects. The presented theoretical a
pproach is formulated as a multiquantum technique to calculate analytically
the resonant laser-molecule interactions and molecular photoprocesses. The
method permits to include the non-linear impact of a resonant laser upon i
ntra-molecular motion beyond an adiabatic approximation and may be applied
for laser intensities until 10(15) W cm(-2). The theory of wave functions a
nd Green's functions of multi-channel Schrodinger equation is elaborated wi
thout perturbative restrictions on inter-channel couplings. The multi-chann
el quasi-classical approximation is developed to integrate the coupled equa
tions for nuclear motion in simple matrix form. The theoretical approach pr
oposed is used to study the intense-field photodissociation and photoabsorp
tion, multi-photon resonant ionization and dissociation, dynamic polarizabi
lity and resonance Raman scattering from rotating diatomic molecules. The w
ell-known laser-induced hardening and softening of intra-molecular bonds ar
e reformulated. The new resonances in the molecular absorption, ionization
and dissociation, arisen in resonant laser fields, are examined too. The ph
enomena of resonant laser field selective orientation and alignment of non-
dipole diatomic molecules, laser-induced molecular dipole moment, temperatu
re-dependent polarization of molecular gases, non-perturbative amplificatio
n of scattered laser radiation in resonant medium are analysed in detail. T
he known experimental observations of laser-induced non-linear effects and
circumstances for new strong-field experiments are discussed. (C) 2000 Else
vier Science B.V. All rights reserved.