| Over the last two decades, extensive studies and research have opened a new era for Fiber Bragg Grating (FBG) based sensing technologies. One of the new applications is the FBG based accelerometers. In various applications, FBG based accelerometers have shown many advantages over the conventional electronic based accelerometers, such as their immunity to electro-magnetic interference, high accuracy and low power consumption.;In 2006, a five-year Research and Development project SEAformatics was initiated; the objective was to develop a compact and low-cost marine sensing system utilizing FBG based accelerometers for ocean floor seismic imaging and earthquake detection. In the early stages of the project, research was focused on the exploration of a new FBG based accelerometer featuring a simple structure design and no complex interrogation system set-ups.;In this thesis, a new FBG based accelerometer design using two gratings is proposed. This accelerometer is combined with an Intensity Modulation-Direct Detection (IM-DD) method for its optical signal interrogation. The technical contents included in the thesis consist of the accelerometer mechanical system modeling and structure design, the introduction on the proposed optical signal interrogation method, the accelerometer parts assembly, interrogation system set-up, and experiments. Results obtained from the experiments have proven that the proposed FBG based accelerometer is practical, and consequently it would provide a good foundation for the development of the entire sensing system. |
