Highly sensitive refractive index sensor based on structure modulation of digital versatile discs

Surface plasmon resonance (SPR) is a key sensing technique for chemical and biological sensor. Recently, researchers proposed different nanostructures for refractive index and bio-sensing [1-4]. In this work, we proposed a high sensitivity refractive index sensor based on modulations of digital versatile discs (DVD) structures. We used laser beam lithography process to fabricate regular substructures on the lands of DVD substrate. We found the modulated structure will narrow the resonance spectrum and improve sensitivity a little. However, the substructure will significantly improve the coupling efficiency of incident light to excite surface plasmon. Based on our fabrication technique, a cheap and uniform surface plasmon resonance (SPR) sensor with sensitivity of 764nm per refractive index unit (nm/RIU) and ~20 figure of merit (FoM) is demonstrated experimentally.