3D bit optical data storage has the ability to reach Tbytes on a recording medium no larger than a compact disc using two-photon excitation and multi-layer recording. The introduction of a poly-vinyl carbazole (PVK) based photorefractive polymer as the recording material allows the system to rewrite the recorded information via the photorefractive effect.[1,2] In this paper, we demonstrate the use of continuous wave illumination for three-dimensional (3D) bit optical data storage under two-photon excitation in a new poly(methylmethacrylate)-based (PMMA) photorefractive polymer. This achievement makes it possible to develop a cheap, compact, sub Tbyte rewritable optical data storage system to further extend the capabilities of compact disc and digital versatile disc technology.