Surface plasmon resonance sensor based on seven-core photonic crystal fiber for refractive index and temperature measurement

A highly sensitive surface plasmon resonance (SPR) sensor based on seven-core photonic crystal fiber (SCPCF) is proposed and experimentally demonstrated for refractive index (RI) and temperature measurement. The dual-parameter sensor is fabricated by inserting an SCPCF between two multimode fibers (MMFs). The surface of SCPCF is covered with gold film as the sensing region. One part of the gold film is additionally coated with polydimethylsiloxane (PDMS) to enable temperature sensing, while the rest is used for RI sensing. The experiment results show that the RI sensitivity and temperature sensitivity of the proposed sensor reach 1644 nm/RIU and −2.59 nm/°C, respectively. Additionally, the SPR dual-parameter sensor based on SCPCF has good stability and repeatability, which has great application potential in the field of environmental monitoring, disease diagnosis, and biochemical sensing.