Femtosecond laser studies of molecular wavepacket dynamics in the cesium dimer

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1993

OSTI ID:7041868

Rodriguez, G

Femtosecond laser pump-probe experiments have been applied to the study of vibrational wavepacket dynamics in the excited states of the cesium dimer, Cs[sub 2]. The real-time vibrational motion of the molecule is observed by probing the quantum motion of the wavepacket on a potential surface by a pair of time-delayed ultrafast laser pulses. Specifically, pumping the C([sup 1][Pi][sub u]) [l arrow] X([sup 1][Sigma][sub g][sup +]) Cs[sub 2] band at several wavelengths between 627 nm and 650 nm produces a wavepacket with an oscillation period of [approximately]1.15 psec. The wavepacket is detected by photoionizing the excited molecule with a time-delayed probe pulse. The wavepacket oscillations persist for approximately 20 psec, and their decay is attributed to the dephasing of the vibrational wavefunctions that comprise the wavepacket. Using the Fast Fourier Transform (FFT) spectral method, numerical quantum calculations of the time dependent Schroedinger equation have been performed to simulate the time evolution of the wavepacket density. The wavepacket simulations reproduce the experimentally observed oscillations, and can be used to describe the classical motion of the molecule.

• Research Organization: Illinois Univ., Urbana, IL (United States)
• OSTI ID: 7041868
• Country of Publication: United States
• Language: English

Related Subjects

664200* -- Spectra of Atoms & Molecules & their Interactions with Photons-- (1992-)
74 ATOMIC AND MOLECULAR PHYSICS
ALKALI METALS
CESIUM
DIFFERENTIAL EQUATIONS
ELEMENTS
ENERGY LEVELS
EQUATIONS
EXCITED STATES
IONIZATION
LASER SPECTROSCOPY
METALS
PARTIAL DIFFERENTIAL EQUATIONS
PARTICLE KINEMATICS
PHOTOIONIZATION
SCHROEDINGER EQUATION
SPECTROSCOPY
VIBRATIONAL STATES
WAVE EQUATIONS
WAVE PACKETS