Hurter-Driffield exposure characteristics of oriented M centers in NaF

Abstract
The dichroism of the M and MA color centers in NaF is used for data storage. Optical‐density–vs–exposure (Hurter‐Driffield) curves are obtained for eight NaF samples with different impurity content and doping. Lithium‐doped NaF samples are found to exhibit a larger dichroism and a better sensitivity and fatigue resistance than other NaF samples.