METHOD FOR QUENCHING PHOTOLUMINESCENCE

PROBLEM TO BE SOLVED: To easily reduce or quench photoluminescence in an optical memory element with aggregates of photoluminescent nanoparticles having a TDLM function by which the intensity of photoluminescence can be increased or increased and memorized as a function of the irradiation time or irradiation dose of exciting light. SOLUTION: When a thin film contg. aggregates of photoluminescent nanoparticles having the TDLM function is used and exposed to exciting light at room temp. in air, the intensity of photoluminescence (fluorescence) from the irradiated region of the thin film increases to several times the initial intensity as a function of the irradiation time (irradiation dose). An arbitrary image can be formed on the thin nanoparticle film by the difference in the intensity of photoluminescence between the irradiated and non-irradiated regions (contrast) on the film.