Other researchers solved this problem by using two laser beams positioned at different angles and aimed at the target. Each beam was composed of photons that were not energetic enough by themselves to change the refractive index but that could do so if they hit the same molecule simultaneously. Only the molecules at the focused beam waist received enough energy to cause two-photon excitation. Other molecules were not excited because the intensity was too low. In contrast, the plastic costs pennies for the same size wafer.
Some obstacles remain.
And after writing, erasing and rewriting at the same location 1000 times, the plastic's refractive index reverts to normal, causing the individual bits to degrade. But Gu said he is optimistic that this technology can break the two-dimensional barrier. He stated that while its current recording speed is slow, the plastic can be read in real time. Laurin Publishing Co. Inc. All rights reserved. Reproduction in whole or in part without permission is prohibited.