Laser controls

As discussed in section A 1.2.17. the existence of the approximate poly ad numbers, corresponding to short-time bottlenecks to energy flow, could be very important in efforts for laser control, apart from the separate question of bifiircation phenomena. 

The various approaches to laser control of chemical reactions have been discussed in detail in several recent reviews [64. 65],... 

Shapiro M and Brumer P 1986 Laser control of product quantum state populations in unimolecular reactions J. Chem. Phys. 84 4103... 

Zare R N 1998 Laser control of chemical reactions Science 279 1875... 

The similar method as that mentioned above can be applied to laser control of chemical dynamics. This will be discussed in Section V. 

Hotta, J., Sasaki, K, Masuhara, H. and Morishima, Y. (1998) Laser-controlled assembling of repulsive unimolecular micelles in aqueous solution. J. Phys. Chem. B, 102, 7687-7690. 

A. D. Bandrauk, Y. Fujimura, and R. J. Gordon (eds.), Laser Control and Manipulation of Molecules, American Chemical Society Oxford University Press, New York 2002 W. Potz and A. Schroeder (eds.), Coherent Control in Atoms, Molecules, and Semiconductors, Kluwer Academic Publishers, Dordrecht, 1999. 

Fig. 6.3. Laser control of high-voltage discharges, (a) Free discharge over 3 m, without laser filaments. Note the erratic path, (b) Straight discharge guided along laser filaments [25]...

Plasma filaments generated in the atmosphere by ultrashort laser pulses therefore appear to be able to trigger electric events in thunderclouds under high positive electric field. This result constitutes a first step towards laser-controlled lightning. 

Dela Cruz, J. M., Lozovoy, V. V., and Dantus, M. 2005. Quantitative mass spectromet-ric identification of isomers applying coherent laser control. J. Phys. Chem. A 109(38) 8447-50. 

W. Jakubetz and B. L. Lan. A simulation of ultrafast state-selective IR-laser-controlled isomerization of hydrogen cyanide based on global 3D ab initio potential and dipole surfaces. Chem. Phys., 217 375-388(1997). 

We start our discussion of laser-controlled electron dynamics in an intuitive classical picture. Reminiscent of the Lorentz model [90, 91], which describes the electron dynamics with respect to the nuclei of a molecule as simple harmonic oscillations, we consider the electron system bound to the nuclei as a classical harmonic oscillator of resonance frequency co. Because the energies ha>r of electronic resonances in molecules are typically of the order 1-10 eV, the natural timescale of the electron dynamics is a few femtoseconds to several hundred attoseconds. The oscillator is driven by a linearly polarized shaped femtosecond... 

Now that this mechanism is understood, relatively simple ultrashort optimal pulse shapes can be used for implementation of this robust approach for laser control of photophysical systems. 

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