A programmable non-volatile grating, based on Phase-Change Materials (PCMs), is used as a core element of a non-volatile optoelectronic memory. The information is stored in the sequence of the grating window of a novel device called Electrically Erasable Programmable Read-Only Grating (EEPROG). The device can be read by scanning a tunable laser source and collecting the power and phase at each scanned wavelength to reconstruct its reflectivity. Phase can be inferred by means of homodyne measurements. The higher the available optical bandwidth at the tunable laser source, the smaller the footprint occupation per bit required for storage. In detail, we demonstrate that a footprint of 4.55 × 4.2 μm is needed for each stored bit, when an available optical bandwidth at the tunable laser source of 61 nm is considered. The possibility of storing information by means of electrodes and reading the same information by means of light enables a series of possible applications in the field of neuromorphic computing.