Enhanced of the Two photon Absorption in Nanostructure Wide Band gap Semiconductor CdS using femtosecond Laser


We observed strong nonlinear absorption in the CdS nanoparticles of dimension in the range 50-100 nm when irradiant with femtosecond pulsed laser at 800 nm and 120 GW/cm2 irradiance intensity. The repetition rate and average power were 250 kHz and 30 mW. The CdS nanoparticles sizes were controlled by reaction time of S-olylamine and Cd-alylamine components interacting at 300 oC. The structures of the prepared CdS nanoparticles was tested and its optical properties were investigated. The nonlinear absorption coefficient was measured using a fully computerized z-scan unit. The results show the value of ß is in order of 116 cm/GW. This value is in a good agreement with values mentioned by other studies.