High resolution coherent control measurements on KRb

We present high resolution optimal control on KRb in a molecular beam. Isotopomer selective ionization is performed by closed loop experiments with a pulse shaper consisting of two liquid crystal masks with 640 pixels each. This yields a spectral resolution of 1.84 cm−1/pixel which is according to our knowledge the highest that have been used for coherent control measurements until now. The isotopomer ratio 124KRb/126KRb is optimized by pure and combined phase and amplitude modulation and the optimized pulse shapes indicate which isotopic composition of the heavier isotopomer mass 126KRb mainly contributes to our measurements. Moreover, the involved vibronic transitions are exposed in the optimized spectra.