A data storage apparatus and method of storing data are disclosed. An array of irradiation sources are provided for writing on an optically stimulated luminescence (OSL) material. The OSL material includes data storage pixels or spots. Each pixel or spot includes gray-scale levels with higher order bits and variable intensity. A light source stimulates luminescence on the OSL material.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
 This invention was made with Government support under Contract DE-AC0576RLO1830 awarded by the U.S. Department of Energy. The Government has certain rights in the invention.