A Free Space Optics Based Identification and Interrogation System

Abstract

In this paper we discuss the design of a free-space optics based system that can be used for identification or identification/interrogation over varying distances. The system consists of photonic transducers and sources that can be easily incorporated in optical tags and base-stations. When an optical reader sends an interrogation beam of light to an optical tag, the tag sends its response. A major advantage of our system is that various electronic or photonic sensors or transducers can be easily incorporated in the design of optical tags so that the output of the sensors can be read remotely. The proposed system does not cause RF interference to nearby objects and is secure owing to the highly directional nature of optical communication. The system can use encryption technology to provide an additional layer of security. Unlike RF-IDs our system also provides flexibility on the distance between tags and base-stations or readers. Further, optical communication is unlicensed unlike the use of RF bands. Optical identification/interrogation systems proposed in the literature either uses specially designed MEMS devices or holograms. Compared to these our system is built with low-cost optoelectronic components and can be packaged in low-cost and rugged units.