A fiber optic imaging sensor is presented that utilizes surface plasmon resonance (SPR) excitation. The configuration of this sensor allows for remote sensing and multiplexing. The sensor is advantageous in that it eliminates the traditional bulk optic prism in favor of a relatively simple and inexpensive design. Two sensor configurations are presented; the principle of one is based on using optical interference, and that of the other is based on using the optical intensity as in traditional bulk-optic SPR imaging systems. Experimental measurements indicate that the fiber optic sensor based on optical interference is compact and immune to noise due to ambient light, and is more powerful and reliable than the common SPR imaging sensor based on optical intensity. Using fiber optics, the theory of SPR, and interference, a new SPR imaging sensor is achieved, which is better fitted to applications.
A Surface Plasmon Resonance(SPR) sensor based on Kretschmann configuration has been setup. In this setup, Ag was applied as supporting metal, and incident angle was fixed. There are two main method, one is Surface Plasmon Microscopy(SPM) based on optical intensity, the other the Surface Plasmon Interference Microscopy (SPIM) based on the theory of Surface Plasmon Resonance and optical interference. SPM and SPIM were analyzed both theoretically and experimentally. Comparing and analyzing the result of theory and experiment, the result shows that SPIM has higher spatial resolution than SPM, and more powerful and immune to noise due to ambient light. So the SPIM is more fitful for sensor applications than SPM.