The process uses minuscule dots called voxels etched in the molecular structure of pure silica glass that bend light to store information (the light itself changes direction as it passes through one depending on thelight's polarization orientation.) The data can then be wiped and rewritten by re-etching the voxels.
Glass has a lot of advantages over other non-volatile memory. In particular, it can withstand temperatures up to 1800F and, since the etchings are located within the structure of the glass itself, the information lasts quite literally forever with no noticeable data degradation.
As research team member, Martynas Beresna, said:
Other uses include cheaper and more compact medical imaging, precise manipulation of atom-sized objects, and even high-resolution imaging far beyond what we see today.