Coherent Wave packet transfer by intense femtosecond pulses ——Theoretical calculation for I2

Kazuhiko Misawa, Isao Matsuda, Naoyuki T. Hashimoto +1 more

A new optical telecommunication method combining time and frequency domain multiplexing is proposed using phase-controlled femtosecond pulses. Each pulse in a pulse train can be used as a data packet with data bits in the frequency domain. We call the new principle ‘wave packet engineering’, which adjusts the amplitude and phase of the wave function in device materials arbitrarily by controlling the spectral phase of femtosecond pulses. The optical phase-to-amplitude converter is demonstrated with organic dye molecules, in which the phase information in the phase-modulated pulses can be demodulated into the luminescence intensity. The luminescence intensity from cyanine dye molecules is observed to be chirp dependent, and is explained quantum mechanically in terms of coherent population transfer. The design principle of the device using semiconductor coupled quantum nanostructures is also discussed in terms of wave packet engineering.

FRANZ HASSELBACH

Charles V. Shank, Robert W. Schoenlein, Daniel M. Mittleman +1 more

C. Meier, Juan Alberto Beswick

The process of decoherence of vibrational states of I2 in a dense helium environment is studied theoretically using the mixed quantum/classical method based on the Bohmian formulation of quantum mechanics [E. Gindensperger, C. Meier, and J. A. Beswick, J. Chem. Phys. 113, 9369 (2000)]. Specifically, the revival of vibrational wave packets is a quantum phenomena which depends sensitively on the coherence between the vibrational states excited by an ultrafast laser pulse. Its detection by a pump-probe setup as a function of rare gas pressure forms a very accurate way of detecting vibrational dephasing. Vibrational revivals of I2 in high pressure rare gas environments have been observed experimentally, and the very good agreement with the simulated spectra confirms that the method can accurately describe decoherence processes of quantum systems in interaction with an environment.

Parvendra Kumar

Jochen Arlt, Carsten Weiss, G. Torosyan +1 more

The pulse reshaping of femtosecond laser pulses tuned to Rydberg transitions of strontium vapor is observed experimentally. We show theoretically that their shape closely reflects the dynamics of Rydberg wave packets induced by the pulses. The decay and compression of Rydberg wave packets excited by both Fourier limited and chirped fs pulses is presented.