Preparation of Ce-doped CaGa2S4 crystals by melting method and their optical properties

Transparent Ce-doped CaGa2S4 bulk crystals were synthesized using a self-flux method. These bulks had high transmittance in luminescence region of 450 nm to 600 nm. Dependence of luminescence intensity on excitation power was observed using a pulsed dye laser excitation.. Saturation of luminescence intensity was observed for the first time in this material when the excitation power density exceeded 10 MW/cm(2). This saturation was assumed to result from excited state absorption (ESA), and analyzed with a 4-level transition model involving ESA.