Optical content addressable memories for data/knowledge base processing

This paper describes the principles and architectures of a one- and a two-dimensional optical content addressable memory (OCAM). These architectures are based on optical matrix multipliers which use free space interconnections in optics. They work as a CAM due to spatial coding used to perform bit matching and masking. A 1-D OCAM can perform a single (one-to-many) search operation and a 2-D OCAM can perform multiple (many-to-many) search operations in one step. An optical database machine (ODM) based on a 2-D OCAM along with a page-oriented holographic memory (POHM) is proposed for the execution of relational database operations