CONTROLLING MOLECULAR ANGULAR-MOMENTUM ORIENTATION BY RAMAN PUMPING AND OPTICAL AC STARK-EFFECT

The anisotropic interaction of an external electric field with the pol arizability of a molecule is investigated for intense optical fields. The ac Stark effect yields an energetic splitting of normally degenera te \ J, m(J)> states. Combined with stimulated Raman pumping the effec t can be exploited to prepare spatially oriented and vibrationally exc ited molecules by tuning the Stokes laser frequency to excite single \ J, m(J)> states. The effect can also be used to directly measure \ m( J)> quantum state distributions, either via Raman probing or in combin ation with other photoexcitation techniques. (C) 1998 Published by Els evier Science B.V. All rights reserved.