SPR Biosensor Based on Microstructured Fiber with Lens Shaped Air Holes

In this work, we propose a microstructured optical fiber with lens shaped air holes as a surface plasmon resonance biosensor. The fiber material is fused silica and in the central core region there is a small air hole which is surrounded by four biconvex lens shaped air holes acting as the cladding. The lens shaped holes helped bring design flexibility to tune sensor performance by enhancing plasmon excitation. The gold layer is placed outside the cladding to expedite real time in situ sensing. We have analyzed the sensor performance by using finite element method. Results have shown a maximum wavelength sensitivity of 5000 nm/RIU, maximum amplitude sensitivity of 500 RIU-1 and a resolution of 2x10(-5) RIU.