An archival waveguide memory device is provided and comprises a large number of elongated waveguides and a series of partially reflective elements distributed within each of the waveguides in accordance with data to be stored within the waveguides so as to act upon an input optical signal in each one of the waveguides and to generate a reflected output optical signal able to be uniquely correlated with the data. A method of recording data in a waveguide is also provided. A method of retrieving data stored in a waveguide is further provided and comprises injecting a pulsed optical signal in the waveguide, detecting a reflected output optical signal from the waveguide, and decoding a temporal variation in the reflected output optical signal to retrieve the data.