New magnetic connector for embedding of optical sensors in composite materials

Abstract

Since the early '80s we begun to talk about the possibility of inserting the optical fiber within the next generation (composite) materials. At the time the optical fiber was used primarily to signals transportation, for communications, and therefore were used primarily multi-modal fibers, not suitable for use with fiber optical sensors, particularly Fiber Bragg Grating (FBG) sensors. It has been started to develop connectors that would allow the embedding of the fibers themselves, allowing an easier outgoing of the termination pigtails from the material itself, [1–3]. Several patents were developed for this purpose, focusing attention, given the almost complete immunity to magnetic fields of optical fiber, to connectors magnetized to facilitate the operation of plug-in. Over the years we have lost trace of these connectors. Today, given the enormous development perspective that the FBG sensors play in the field of real time structural health monitoring, we are turning our attention to the need for a connector easy, quick and effective to plug, that size does not interfere with the structure to be monitored, easy to make and assemble, in a word, practical, from all points of view. For this reason we have designed a miniaturized magnetic connector that is optimized for connecting the single-mode optical fiber, typically used for FBG sensors, which allows efficient transport of the signal, minimizing losses and allow seamless integration with the material, and the structure to be monitored, in other words, this connecting system has been designed in order to develop a product which solves the problem shown by commercial available connectors during their embedding inside materials‥