Synthesis of selenium nanoparticles and their nonlinear optical properties

Selenium nanoparticles were fabricated using a physical deposition method based on heterogeneous condensation. The Selenium nanoparticles were deposited on a quartz substrate and the ultrafast nonlinear optical responses were investigated by using the Z-scan technique. The nanosize films showed two-photon absorption and a large positive nonlinear refractive index at 800 nm excitation wavelength. The obtained real and imaginary parts of the intensity-dependent complex third-order nonlinear susceptibility of the Selenium nanoparticles ranged from 10(-11) to 10(-8) (esu) for different irradiance levels.