Abstract

Metal particle composites have been demonstrated to exhibit third-order nonlinearities in optical waveguides comparable to CdS_x Se_1-x glasses. Ag-ion exchange waveguides are also known to contain varying amounts of Ag metal aggregates depending on the Ag concentration of the melt used in fabrication. Reported here is the demonstration and measurement of the associated nonlinearity using four-wave mixing. Since the fraction of metallic Ag in the waveguides may be controlled predictably in the fabrication process, the nonlinearity can be tailored into the waveguide structure using standard photolithographic techniques. The waveguides were prepared using a standard Na-Ag exchange process from a dilute Ag NO₃/NaNO₃ melt at 300°C. The concentration of Ag metal particles as opposed to exchanged Ag (oxide) in glass was determined from absorption measurements combined with a material analysis of the total Ag profile using an electron microprobe technique. Reflectivities as high as 0.5% were measured in waveguides with high metallic Ag concentration. By comparison, waveguides with very low absorption (low metallic Ag) showed no measurable reflectivity.

© 1989 Optical Society of America