Linear and nonlinear optical characterization of Ga nanoparticle monolayers

Single layers of quasi-spherical metal nanoparticles of uniform and control led size were fabricated by evaporation-condensation in ultrahigh vacuum, e xploiting the partial wetting of Ga with respect to the underlying SiOx mat rix. The net linear and nonlinear optical response of such self-assembled l iquid Ga nanoparticles was determined using CW optical methods as well as p ulsed laser excitation. Second, harmonic generation was observed in transmi ssion using femtosecond laser pulses. The fluence, polarization and azimuth angle dependence as well as the second-harmonic (SH) signal dependence on particle size are presented and discussed. (C) 2001 Elsevier Science B.V. A ll rights reserved.