Three-dimensional laser alignment of polyatomic molecular ensembles

Abstract

We explore the physics of alignment and three-dimensional alignment of polyatomic molecular ensembles in moderately-intense laser fields. To that end we develop a purely classical approach to molecular alignment and compare its results with those of quantum mechanical calculations in appropriate limits, finding qualitative agreement. The method is applied to explore a new phenomenon in strong field coherent control that is unique to the ensemble case, namely the formation of organized assembly due to induced dipole–induced dipole interactions at sufficiently large intensities or/and densities. The effects of the laser field polarization, its intensity, and the initial rotational temperature on the degree of alignment and the translational and orientational order of the assembly are investigated.

Keywords:

• molecular alignment
• moderately-intense laser field
• induced dipole moment
• molecular clustering

Acknowledgements

We are grateful to the Department of Energy (Grant No. DE-FG02-04ER15612) for support.