Optical modulation of near-infrared photoluminescence from lead sulfide quantum dots in glasses

The authors report the modulation of photoluminescence intensity from lead sulfide quantum dots using two laser beams with different wavelengths. Photoluminescence from lead sulfide quantum dots in glasses was reversibly switched between the “bright” and “dark” states and degree of darkening to 16% of the initial intensity was realized. Changes in the photoluminescence were insensitive to temperature but strongly dependent on the power densities of the modulating laser beam. This efficient optical modulation has potential for optical switching and memory device applications.