Singly, doubly and triply resonant multiphoton processes involving autoionizing states in magnesium


Autoria(s): Kylstra, N.J.; Joachain, C.J.; Van Der Hart, H.W.; Burke, P.G.
Data(s)

28/07/1998

Resumo

Using the R-matrix Floquet theory we have carried out non-perturbative, ab initio one- and two-colour calculations of the multiphoton ionization of magnesium with the laser frequencies chosen such that the initial state of the atom is resonantly coupled with autoionizing resonances of the atom. Good agreement is obtained with previous calculations in the low-intensity regimes. The single-photon ionization from the 3s3p P excited state of magnesium has been studied in the vicinity of the 3p S autoionizing resonance at non-perturbative laser intensities. Laser-induced degenerate states (LIDS) are observed for modest laser intensities. By adding a second laser which resonantly couples the 3p S = and 3p3d P autoionizing levels, we show that, due to the small width of the 3p3d P state, LIDS occur between this state and the 3s3p P state at intensities of the first laser below 10 W cm . We next investigate the case in which the first laser induces a resonant two-photon coupling between the ground state and the 3p S autoionizing state, while the second laser again resonantly couples the respective 3p S and 3p3d P autoionizing states. At weak intensities, our calculations compare favourably with recent experimental data and calculations. We show that when the intensity of the first laser is increased, the effect of an additional autoionizing state, the 4s5s S state, becomes significant. This state is coupled to the 3p3d P autoionizing level by one photon, inducing a triply resonant processes. We show that LIDS occur among the three autoionizing levels and we discuss their effect on the decay rate of the ground state. We consider dressed two- and three-level atoms which can be used to model the results of our calculations.

Identificador

http://pure.qub.ac.uk/portal/en/publications/singly-doubly-and-triply-resonant-multiphoton-processes-involving-autoionizing-states-in-magnesium(797cd723-88d6-4729-a0b4-586542bf796f).html

http://dx.doi.org/10.1088/0953-4075/31/14/009

http://www.scopus.com/inward/record.url?partnerID=yv4JPVwI&eid=2-s2.0-0032114761&md5=704d49f0d01ec6558cb600c7ee72d0d2

Idioma(s)

eng

Direitos

info:eu-repo/semantics/restrictedAccess

Fonte

Kylstra , N J , Joachain , C J , Van Der Hart , H W & Burke , P G 1998 , ' Singly, doubly and triply resonant multiphoton processes involving autoionizing states in magnesium ' Journal of Physics B: Atomic, Molecular and Optical Physics , vol 31 , no. 14 , pp. 3089-3116 . DOI: 10.1088/0953-4075/31/14/009

Palavras-Chave #/dk/atira/pure/subjectarea/asjc/3100 #Physics and Astronomy(all) #/dk/atira/pure/subjectarea/asjc/3100/3107 #Atomic and Molecular Physics, and Optics
Tipo

article