ANGULAR-DISTRIBUTIONS OF THE PRODUCTS OF DISSOCIATIVE IONIZATION OF MOLECULES BY INTENSE LASER FIELDS

Large dipole moments can be induced in molecules by intense, linearly polarized light fields. Such dipole moments exert large torques on mol ecules, which can swamp rotational motion, and give rise to spatial al ignment of linear molecules along the direction of the light polarizat ion vector. Pendular states are formed. Signatures of such aligned sta tes, some of which also manifest the effects of pendular motion, have been obtained in experiments which measure the angular distributions o f fragment ions produced when molecules undergo dissociative ionizatio n due to interaction with linearly polarized laser radiation at a wave length of 532 nm at intensities of the order 10(13) W cm(-2). Effects of space charge saturation on such angular distributions are explored by conducting experiments at different laser intensities and using two different laser-molecule interaction geometries. Experimental results for the linear triatomic CS2, bent triatomics NO2 and SO2, and a tetr ahedral polyatomic CCl4 are compared with model calculations and ab in itio molecular structure computations.