LSPR Sensor Employing Side-Polished Suspend-Core Microstructured Optical Fiber With a Silver Nanorod

A highly sensitive refractive index (RI) sensor based on localized surface plasmon resonance (LSPR) with side-polished suspend-core microstructured optical fiber has be propsed. By depositing a silver nanorod on the fiber core surface in the side-polished hole, the fundamental mode was not enchained in the suspended core area, and coupling partially to the surface of silver nanorod, which result in the enhanced LSPR phenomenon. The RI sensing characteristics of the proposed sensor were investigated theoretically. Meanwhile, three optimization schemes were presented to improve the RI sensing performance including the diameter and metal materials of nanorod and the number of silver nanorod. A high RI sensing sensitivity of 8600 nm/RIU was achieved at the RI of 1.40 and the silver nanorod diameter of
$0.7~\mu \text{m}$
, which shown that the RI sensing sensitivity could be effectively improved by the LSPR effect. The great RI sensing performance of the proposed sensor has the potential to be used in the field of biomolecular measurement and environment quality-detection.