High harmonic generation in organic molecules

Summary form only given. High harmonic generation (HHG) in monatomic gases is well understood and small molecules have been found to behave in a similar way. The efficiency of harmonic generation is approximately predicted by the static polarisability of the species and the maximum harmonic order increases with the ionisation potential of the species and the ponderomotive potential of the laser field. Larger molecules introduce additional features which are expected to influence the harmonic generation process. To investigate the dependence of HHG processes on molecular properties, such as geometry, size, type of bonding and the role of electron delocalisation, we present here the results of a study performed on the molecules of benzene (C/sub 6/H/sub 6/) and cyclohexane (C/sub 6/H/sub 12/). Their harmonic response was compared with the rare gas xenon.