FIELD: optical data storage and processing. SUBSTANCE: multistable optical logic gate has light-sensitive organic material 1 subjected to photochemical cycle at several physical states by irradiating it with light, its physical state being assigned to logic value that can be varied by means of optical addressing of gate; the latter is initially in preset monostable state prior to being addressed. Multistable optical logic gate is made directly addressable due to provision of at least one chromatic light source 2 for optical addressing and at least one light-sensitive optical detector 5 adjacent to light-sensitive material. Method for producing light-sensitive material 1 involves organizing desired initial metastable state in photochemical cycle and assigning definite logic value to gate. Method for optical addressing of optical logic gate provides for respective writing and storage, reading, erasing, and switching steps including excitable transitions between states in photochemical cycle and state detection. It is used in optical logic device for data saving and processing. EFFECT: facilitated addressing operations implemented in the form of direct addressing for writing, reading, storage, and the like. 34 cl, 12 dwg
