The development of an optical-based dosimeter for neutrons and heavy charged particles is described. It is based on the use of three dimensional (3-D) optical memory materials, used in optical computing applications, and multiphoton fluorescence of photochromic dyes. Development and characterization of various types of dosimeter materials are described as well as the optical readout system. In addition, various excitation geometries for `reading' and `writing' to the optical memories are also discussed.