Optical Storage Medium and Process

A data storage process which includes an erasable high speed, high density, storage medium having a transition metal oxide layer where said oxide layer is capable of undergoing an optically readable chemical change when simultaneously exposed to heat and to light of a selected wavelength. An optically readable image is formed in selected regions of the oxide layer under ambient conditions which include O2 by simultaneously exposing said layer to heat and to radiation in the blue-green or shorter wavelength spectrum. The image is erased by heating the entire medium using a furnace or by heating selected portions with IR radiation.