Multiplexing Optical Information Storage in Diamond

High-capacity storage is crucial in the information age. Optical information storage, owing to low cost and robustness, has served as a prominent choice for storing a colossal volume of data. However, the capacity is limited by the binary information encoding; i.e., each pitch stores just a single bit. Here, we demonstrate a multidimensional, grayscale optical information storage based on charge state conversion of color centers in diamond. We observe that the bright and dark states of the nitrogen vacancy (NV) and silicon vacancy (SiV) centers are spatially complementary, achieving a contrast ratio of 7:1 and enabling multigray-level information encoding. Based on the strategy of encoding multiplexing information, the storage capacity can be effectively increased. Meanwhile, the “white-light-erasable” feature protects the data from secondary leakage. This work contributes significantly to the development of advanced diamond storage technologies.