The nonlinear optical properties of silicon nanoclusters made by laser ablation and ion implantation

Summary form only given. Recent measurements of high optical nonlinearity in Si nanoclusters has generated interest in their potential use as an optical switch. The study of the nonlinear optical properties of Si nanoclusters (NCs) made by laser ablation and ion implantation techniques is motivated by the need for materials that exhibit large values of the real part of the third order nonlinear susceptibility (/spl chi//sup (3)//sub Re/). This is essential for light controlled phase or refractive index modulation at low power. The novelty of laser ablated Si NCs embedded in a silica substrate is that the measured large nonlinearity results from the deposition of micron-sized droplets of Si composed of close-packed nanocrystallites of Si (3-50 nm). Z-scan measurements were performed to measure the real and imaginary part of /spl chi//sup (3)/, where the nonlinear refractive index (n/sub 2/) is related to /spl chi//sup (3)//sub Re/ and the nonlinear absorption (/spl beta/) to /spl chi//sup (3)//sub lm/.