Theory And Designs Of Fiber Optic Surface Plasmon Resonance (FO-SPR) Sensor

Surface plasmon resonance (SPR) is an electromagnetic phenomenon of electronic oscillation excited by evanescent wave along the metal surface. The sensor, which uses this technology, is capable of detecting small changes of index of refraction which occur within nanometers of the sensor's surface, so it is used wildly in life science and biomedicine. A fiber optic SPR (FO-SPR) sensor is a novel sensor which combines the optical fiber technology with SPR effect ingeniously. This design not only is cheaper and lighter than prism-based design, but also allow several probes to use at the same time, thus it has been the highlight of sensors field.Recently, the important problem of FO-SPR sensor is how to obtain high susceptibility and long lifetime. The main innovations in the thesis are some novel designs of sensor probes, including four layers FO-SPR sensor and bimetallic layers FO- SPR sensor, which sensing characters are analyzed, and the results show that these new designs can solve these important problems to a great extent.The specific content:Firstly, the principle of SPR and its exciting conditions are respectively discussed in the thesis. Some characters of surface plasmon wave and exciting methods are analyzed based on optics and electromagnetics.Secondly, three layers FO-SPR sensor, with the configuration of fiber optic core, metal film, and sample, is analyzed with simplified modal, and the result coincides with the referees'; Four layers FO-SPR sensor, with the configuration of fiber optic core with high refractive index, buffer waveguide, metal layer and sample, is designed to get high sensitivity and other measuring range; A kind of bimetallic layers FO-SPR sensor (silver/gold layer) is designed, which possesses both high sensitivity and long lifetime.At the end, our main research works are summed up and the possible development of FO-SPR sensor are pointed out.