Towards 5D Optical Data Storage with High Writing Speed

Due to the information explosion in the 21st century, data storage technologies to meet the growing demand for information preservation have attracted considerable interest. Based on self-assembled nanogratings produced by ultrafast laser writing in silica glass, recording and retrieval of multiplexed digital data with a nearly unlimited lifetime was demonstrated [1] . Three spatial dimensions and two optical ones (the slow axis orientation and the retardance) were exploited to realize 5D data storage. However, the drawbacks of low optical transmission in the visible range and low writing speed hinder its utility in practical applications. Recently, a new type of ultrafast laser-induced modification in silica glass, which consists of randomly distributed nanopores, was demonstrated, providing controllable birefringent structures with transmittance as high as 99% in the visible range [2] , [3] . 5D optical data storage with ultrahigh readout accuracy of multilayer data, up to 100% was achieved [4] , but with the drawback of low writing speed of 0.2 kB/s. Here, we report nanopores-based 5D data storage with an increased data writing speed up to 8 kB/s and higher data capacity by tighter focusing in combination with higher repetition rate, maintaining ultrahigh readout accuracy.