Use of quantum dot nanocrystals for spectrally encoded optical data storage

In this paper, we demonstrate the spectral encoding capability of quantum dot nanocrystals (QDs). We mixed two different sizes of QDs in a resin, and two-photon excitation at various wavelengths showed that the relative intensities of the fluorescence from two QDs varied significantly. Such a difference in level of absorption at different wavelengths allows one to record information only on one size of QDs, without affecting the other sized QDs. This property can be applied to optical data storage, so that storage density can be greatly improved.