Optical transient resonance of copper nanoparticle composites synthesized by negative ion implantation

Steady-state optical absorption and nonlinear transient resonance have been studied for Cu nanoparticle composites, fabricated in magnesium aluminate spinel by high-current negative ion implantation. The implantation was conducted at high ion fluxes of 60 keV up to a total dose of 3×1016 ions/cm2. Optical absorption strongly depended on dose rate, ranging from 1 to 100 μA/cm2. The dose rate dependence of the absorption spectra around the surface plasmon resonance behaved analogously to that of a-SiO2, though the radiation-induced absorption band depended on stoichiometry of the spinel. The spectral shape of transient absorption at various dose rates is similar but the bleached plasmon band shifts is in parallel with the steady-state surface plasmon resonance. The dose rate chiefly influences dielectric properties of a spinel matrix but not that of particles.