DEGENERATE 4-WAVE MIXING IN COLLOIDAL GOLD AS A FUNCTION OF PARTICLE-SIZE

The conjugate reflectivity of colloidal gold has been measured for four samples containing particles with mean sizes of 5, 10, 15, and 30 nm. The response times of the samples indicate a size dependence, but the conjugate signal strength was found to be only weakly dependent on particle size. Calculations of the local-field enhancement in the host matrix by the effective-medium theory indicate that the nonlinearity is inherent in the gold particles. © 1990 Optical Society of America.