Field-Free Three-Dimensional Alignment of Polyatomic Molecules

Field-free three-dimensional alignment of polyatomic molecules.

We experimentally demonstrate field-free, three-dimensional alignment (FF3DA) of polyatomic asymmetric top molecules. We achieve FF3DA in sulfur dioxide gas using two time-delayed, orthogonally polarized, nonresonant, femtosecond laser pulses. Our method avoids the use of rotational revivals and is therefore more robust to temperature. The alignment is probed using time-delayed coincidence Coul...

Field-free three dimensional molecular axis alignment.

We investigate strategies for field-free three dimensional molecular axis alignment using strong nonresonant laser fields under experimentally realistic conditions. Using the polarizabilites and rotational constants of an asymmetric top rotor molecule (ethene, C2H4), we consider three different methods for axis alignment of a Boltzmann distribution of rotors at 4 K. Specifically, we compare the...

Doppler-free saturation spectroscopy of pOlyatomic molecules:

Doppler-free spectra of two vibronic bands in the Ä (IB 3u ).-X (lAg) transition of the photochemically instable s-tetrazine (H2C2N4 ) are presented. For the first time saturation spectroscopy is successfully applied to a large polyatomic molecule. Photochemical decomposition of s-tetrazine molecules takes place after excitation and prevents the molecule from returning to the ground state by ra...

Optical gratings induced by field-free alignment of molecules

Alignment-assisted field-free orientation of rotationally cold CO molecules

We follow the alignment-assisted orientation technique proposed by Zhang et al. [Phys. Rev. A 83, 043410 (2011)] to experimentally demonstrate a substantial enhancement of the field-free orientation by using a combination of singleand two-color laser pulses. When a two-color orienting pulse is preceded by a single-color aligning pulse by a suitable time, the resulting orientation is thrice as l...