We theoretically study the control of two-photon excitation to bound and dissociative states in a molecule induced by trains of laser pulses, which are equivalent to certain sets of spectral phase modulated pulses. To this end, we solve the time-dependent Schr\"odinger equation for the interaction of molecular model systems with an external intense laser field. Our numerical results for the temporal evolution of the population in the excited states show that, in the case of an excited dissociative state, control schemes, previously validated for the atomic case, fail due to the coupling of electronic and nuclear motion. In contrast, for excitation to bound states the two-photon excitation probability is controlled via the time delay and the carrier-envelope phase difference between two consecutive pulses in the train.We theoretically study the control of two-photon excitation to bound and dissociative states in a molecule induced by trains of laser pulses, which are equivalent to certain sets of spectral phase modulated pulses. To this end, we solve the time-dependent Schr\"odinger equation for the interaction of molecular model systems with an external intense laser field. Our numerical results for the temporal evolution of the population in the excited states show that, in the case of an excited dissociative state, control schemes, previously validated for the atomic case, fail due to the coupling of electronic and nuclear motion. In contrast, for excitation to bound states the two-photon excitation probability is controlled via the time delay and the carrier-envelope phase difference between two consecutive pulses in the train.

Physical Review ADec 8, 20110 citations

V Coherent Population Trapping in Laser Spectroscopy

E. Arimondo

Progress in opticsJan 1, 19961,158 citations

Production of Non-Equilibrium Atomic Populations by Tunable Laser Excitation

Thomas J. Mcilrath

Springer eBooksJan 1, 19710 citations

Orientation observed by Zeeman spectra of dissociated atoms and the interference in photoexcitations

Yasuyuki Kimura, Shunji Kasahara, Hajime Katô +1 more

In a magnetic field, the wave number of a pump laser light polarized along the field was fixed to the isolated ${\mathrm{Cs}}_{2}D{}^{1}{\ensuremath{\Sigma}}_{u}^{+}(v=46,J=54)\ensuremath{\leftarrow}X{}^{1}{\ensuremath{\Sigma}}_{g}^{+}(v=0,J=55)$ line, and the excitation spectrum of the dissociated $\mathrm{Cs}(6p{}^{2}{P}_{3/2})$ atoms was measured by scanning the wave number of a probe laser light polarized perpendicular to the field. The population of each sublevel $6p{}^{2}{P}_{{3/2,m}_{j}}$ of the dissociated atoms was determined from the line intensities in the ${m}_{j}$ -resolved excitation spectrum. The unequal population between the $6p{}^{2}{P}_{3/2,+|{m}_{j}|}$ and $6p{}^{2}{P}_{3/2,\ensuremath{-}|{m}_{j}|}$ levels (atomic orientation) was observed and it was enhanced as the magnetic-field strength was increased. The atomic orientation is shown to be induced by the interference between the indirect predissociation, which occurs by a combination of the spin-orbit coupling of the $D{}^{1}{\ensuremath{\Sigma}}_{u}^{+}$ state with the ${(2)}^{3}{\ensuremath{\Pi}}_{0u}$ state and the L-uncoupling and Zeeman interactions between the ${(2)}^{3}{\ensuremath{\Pi}}_{0u}$ and dissociative ${(2)}^{3}{\ensuremath{\Sigma}}_{u}^{+}$ states, and the dissociation following a direct excitation to the ${(2)}^{3}{\ensuremath{\Sigma}}_{u}^{+}$ state, which is allowed by spin-orbit coupling of the ${(2)}^{3}{\ensuremath{\Sigma}}_{u}^{+}$ state with the $B{}^{1}{\ensuremath{\Pi}}_{u}$ state. It is demonstrated that the atomic orientation is produced by the photodissociation in the presence of an external magnetic field even when all degenerated molecular $M=J,\dots{},0,\dots{},\ensuremath{-}J$ sublevels are excited by a light polarized linearly along the field.In a magnetic field, the wave number of a pump laser light polarized along the field was fixed to the isolated ${\mathrm{Cs}}_{2}D{}^{1}{\ensuremath{\Sigma}}_{u}^{+}(v=46,J=54)\ensuremath{\leftarrow}X{}^{1}{\ensuremath{\Sigma}}_{g}^{+}(v=0,J=55)$ line, and the excitation spectrum of the dissociated $\mathrm{Cs}(6p{}^{2}{P}_{3/2})$ atoms was measured by scanning the wave number of a probe laser light polarized perpendicular to the field. The population of each sublevel $6p{}^{2}{P}_{{3/2,m}_{j}}$ of the dissociated atoms was determined from the line intensities in the ${m}_{j}$-resolved excitation spectrum. The unequal population between the $6p{}^{2}{P}_{3/2,+|{m}_{j}|}$ and $6p{}^{2}{P}_{3/2,\ensuremath{-}|{m}_{j}|}$ levels (atomic orientation) was observed and it was enhanced as the magnetic-field strength was increased. The atomic orientation is shown to be induced by the interference between the indirect predissociation, which occurs by a combination of the spin-orbit coupling of the $D{}^{1}{\ensuremath{\Sigma}}_{u}^{+}$ state with the ${(2)}^{3}{\ensuremath{\Pi}}_{0u}$ state and the L-uncoupling and Zeeman interactions between the ${(2)}^{3}{\ensuremath{\Pi}}_{0u}$ and dissociative ${(2)}^{3}{\ensuremath{\Sigma}}_{u}^{+}$ states, and the dissociation following a direct excitation to the ${(2)}^{3}{\ensuremath{\Sigma}}_{u}^{+}$ state, which is allowed by spin-orbit coupling of the ${(2)}^{3}{\ensuremath{\Sigma}}_{u}^{+}$ state with the $B{}^{1}{\ensuremath{\Pi}}_{u}$ state. It is demonstrated that the atomic orientation is produced by the photodissociation in the presence of an external magnetic field even when all degenerated molecular $M=J,\dots{},0,\dots{},\ensuremath{-}J$ sublevels are excited by a light polarized linearly along the field.

Physical Review AJun 27, 20032 citations

Selective Excitation by Photodissociation of Molecules

C. R. Gould

Quantum ElectronicsJan 1, 19640 citations

Laser Induced Dissociation Control of $H_2^+$ and $H_3^{2+}$ Laser Induced Dissociation Control of $H_2^+$ and $H_3^{2+}$

Z.-M. Jia, Zhinan Zeng

Laser induced dissociation control of the symmetric diatomic molecular ion $H_2^+$ and the triatomic molecular ion $H_3^{2+}$ is discussed. The simulation results demonstrate that a long-wavelength terahertz or mid-infrared laser pulse can be used to control the electrons of the dissociative states after the excitation of an ultrashort ultraviolet (UV) laser pulse. For $H_2^+,$ there exists an effective time, which increases with increasing pulse duration of the UV laser pulse, for controlling the molecular dissociation. For the electrons of the $1sσ_g$ state, they move along the polarization direction of the dissociation control electric field. In contrast, for the electrons of the $2pσ_u$ state, they move in the opposite direction to that of the electric force. And for the triatomic molecule $H_3^{2+}$ , the electron dissociation control can also be realized by changing the central wavelength of the exciting UV pulse.Laser induced dissociation control of the symmetric diatomic molecular ion $H_2^+$ and the triatomic molecular ion $H_3^{2+}$ is discussed. The simulation results demonstrate that a long-wavelength terahertz or mid-infrared laser pulse can be used to control the electrons of the dissociative states after the excitation of an ultrashort ultraviolet (UV) laser pulse. For $H_2^+,$ there exists an effective time, which increases with increasing pulse duration of the UV laser pulse, for controlling the molecular dissociation. For the electrons of the $1sσ_g$ state, they move along the polarization direction of the dissociation control electric field. In contrast, for the electrons of the $2pσ_u$ state, they move in the opposite direction to that of the electric force. And for the triatomic molecule $H_3^{2+}$, the electron dissociation control can also be realized by changing the central wavelength of the exciting UV pulse.

The Journal of Atomic and Molecular SciencesAug 1, 20170 citations

\mathrm{Cs}(6p{}^{2}{P}_{3/2})

atoms was measured by scanning the wave number of a probe laser light polarized perpendicular to the field. The population of each sublevel

6p{}^{2}{P}_{{3/2,m}_{j}}

of the dissociated atoms was determined from the line intensities in the

{m}_{j}

-resolved excitation spectrum. The unequal population between the

6p{}^{2}{P}_{3/2,+|{m}_{j}|}

and $6p{}^{2}{P}_{3/2,\ensuremath{-}|{m}_{j}|}$ levels (atomic orientation) was observed and it was enhanced as the magnetic-field strength was increased. The atomic orientation is shown to be induced by the interference between the indirect predissociation, which occurs by a combination of the spin-orbit coupling of the $D{}^{1}{\ensuremath{\Sigma}}_{u}^{+}$ state with the ${(2)}^{3}{\ensuremath{\Pi}}_{0u}$ state and the L-uncoupling and Zeeman interactions between the ${(2)}^{3}{\ensuremath{\Pi}}_{0u}$ and dissociative ${(2)}^{3}{\ensuremath{\Sigma}}_{u}^{+}$ states, and the dissociation following a direct excitation to the ${(2)}^{3}{\ensuremath{\Sigma}}_{u}^{+}$ state, which is allowed by spin-orbit coupling of the ${(2)}^{3}{\ensuremath{\Sigma}}_{u}^{+}$ state with the $B{}^{1}{\ensuremath{\Pi}}_{u}$ state. It is demonstrated that the atomic orientation is produced by the photodissociation in the presence of an external magnetic field even when all degenerated molecular $M=J,\dots{},0,\dots{},\ensuremath{-}J$ sublevels are excited by a light polarized linearly along the field.

Laser Induced Dissociation Control of

H_2^+

and

H_3^{2+}

Laser induced dissociation control of the symmetric diatomic molecular ion

H_2^+

and the triatomic molecular ion

H_3^{2+}

is discussed. The simulation results demonstrate that a long-wavelength terahertz or mid-infrared laser pulse can be used to control the electrons of the dissociative states after the excitation of an ultrashort ultraviolet (UV) laser pulse. For

H_2^+,

there exists an effective time, which increases with increasing pulse duration of the UV laser pulse, for controlling the molecular dissociation. For the electrons of the

1sσ_g

state, they move along the polarization direction of the dissociation control electric field. In contrast, for the electrons of the

2pσ_u

state, they move in the opposite direction to that of the electric force. And for the triatomic molecule

H_3^{2+}

, the electron dissociation control can also be realized by changing the central wavelength of the exciting UV pulse.