Novel photochromic glass can store rewritable 3D patterns long term

For decades researchers have been exploring how to store data in glass because of its potential to hold information for a long time -- eons -- without applying power. A special type of glass that changes color in different wavelengths of light, called photochromic glass, holds promise for stable, reusable data storage. Now, researchers have developed a doped photochromic glass that has the potential to store rewritable data indefinitely.