Spatial alignment of molecules by intense, linearly-polarized light fields and the effects of space charge

Angular distributions are measured of S+ and S2+ fragment ions formed by dissociative ionization of CS2 by intense (1013 W cm−2), 532 nm laser pulses of 35 ps duration. Pronounced anisotropies are observed which are indicative of the degree of spatial alignment of the precursor molecules along the direction of the laser polarization vector. Measurements made under different target-density conditions indicate that space charge and laser intensity are two factors which determine the “tightness” with which field-induced spatial alignment of molecules is achieved.