Surface Plasmon Resonance-Based Optical Fiber Embedded in PDMS for Temperature Sensing

• Published in: IEEE journal of selected topics in quantum electronics 2017-03, Vol.23 (2), p.126-131
• Main Authors: Velazquez-Gonzalez, Jesus Salvador, Monzon-Hernandez, David, Martinez-Pinon, Fernando, May-Arrioja, Daniel Alberto, Hernandez-Romano, Ivan
• Format: Article
• Language: English
• Subjects: Fiber optics sensors; Gold; Optical fiber sensors; Optical fibers; polydimethylsiloxane (PDMS); Sensitivity; surface plasmon resonance (SPR); temperature measurement; Temperature sensors
• ISSN: 1077-260X; 1558-4542
• DOI: 10.1109/JSTQE.2016.2628022

A compact, simple-to-fabricate, low-cost, and highly sensitive optical fiber temperature sensor based on surface plasmon resonance (SPR) is reported. The sensor consists of a core mismatch fiber structure fabricated by splicing a small piece of single-mode fiber (SMF) between two multimode fibers (MMF). SPR is generated when evanescent field interacts with the gold layer deposited over the SMF cladding. Then, the sensor was embedded in polydimethylsiloxane (PDMS), which acts as a temperature to refractive index transducer. Due to PDMS high thermooptic coefficient, the SPR dip underwent a noticeable wavelength shift when a variation of temperature occurred. The device was tested in the 20-60 °C range showing a linear response and a sensitivity of 2.60 nm/°C. This sensor is appealing for temperature monitoring in microfluidic devices made of PDMS due to its high performance and simply fabrication process.