An optical memory module comprises one or more memory devices configured to store data, and one or more optical interface modules configured to perform optical communication between the memory devices and an external device. Each of the optical interface modules comprises an input-output light distribution unit configured to divide received light to produce transmission light and reception light, an electrical-to-optical conversion unit configured to perform optical modulation based on the transmission light and an electrical transmission signal to generate an optical transmission signal, and a coherent optical-to-electrical conversion unit configured to perform a coherent reception based on the reception light and an optical reception signal to generate an electrical reception signal.