Second harmonic generation in deposited clusters

We analyse theoretically the generation of second and higher harmonics for sodium clusters deposited on an insulating surface. To this end, we use the time-dependent local-density approximation solved on a three-dimensional g rid. We explore the impact of the various laser parameters (intensity, freq uency, polarisation) on the efficiency of second harmonic generation. The s uccess sensitively depends on a proper tuning of these parameters. We find optimum conditions for which the laser frequency is half the resonance freq uency of the system, if the polarisation is directed orthogonal to the surf ace of the substrate, and if the intensity is large but safely below the cr itical value for destruction of the electron cloud.