Microstructured polymer optical fiber-based surface plasmon resonance sensor

Abstract

ABSTRACT We propose a surface plasmon resonance sensor based on microstructured polymer optical fiber (mPOF) made of polymethyl methacrylate (PMMA) with the cladding having only one layer of air holes near the edge of the fiber. In such sensor, the nanoscale silver metal film can be deposited on the outer side of the fiber, which is easily realized. Numerical simulation results show that spectral an d intensity sensitivity are in the range of 8.3×10 -5 ~9.4×10 -5 RIU . Key words: microstructured polymer optical fiber, surface plasmon resonance, sensor 1. INTRODUCTION Surface plasmon resonance-based sensing method is currently considered to be the most advanced real-time and label-free detection technology. Propagating at the metal–di electric interface, surface plasmons are extremely sensitive to changes in the refractive index of the dielectric. This feature constitutes the core of many surface plasmon resonance (SPR) sensors [1] . Over the past decades, the SPR technology has developed rapidly, and been widely used in the chemical, biological, environmental, pharmaceutical an d other fields. In recent years, many specialists and scholars put forward photonic crystal fiber (PCF) based SPR sensors. The sensing mechanism is though coupling the leaky core mode to the plasmon to achieve resonance sensing. The use of the photonic crystal fiber, with its flexible design, makes it easy to equate the effective index of the core mode to that of the material under test. Thus phase matching condition between the core m ode and the plasmon can be easily achieved at the required wavelength and then resonance occurs. Especially ethe fabrication of sensors doesn’t need removing cladding or tapering fibers as traditional fibers do. So there is no problem in the sensor package. Many scientists have put forward a lot of surface plasmon resonance sensor designs based on PCFs and plenty of simulations and calculations have been made, showing great advantages and good application prospects of the new sensors. In 2006 Hassani proposed PCF-based SPR sensors and optimized micro-fluid design concepts, and refractive index resolution of 10