A Flexible Plasmonic Array with Both High Q‐Factor and Strong Near‐Field

Abstract A higher quality (Q) factor and a stronger near field are two major advantages for surface plasmon resonance (SPR) applications based on high‐performance nanocavities. However, achieving a plasmonic structure that possesses both an ultra‐high Q‐factor and strong near‐field intensity has received relatively little attention. In this work, plasmonic arrays that offer a tunable Q‐factor, tunable near‐field intensity, and excellent uniformity over a centimeter‐scale area are fabricated on a flexible substrate. The flexibility and uniformity of this plasmonic array have been confirmed by its integration into stable optofluidic sensing systems. An in‐depth investigation into its sensitivity and figure of merit (FOM) highlights the superior performance of plasmonic sensing arrays that feature both an ultra‐high Q‐factor and a strong near‐field. This plasmonic array, together with its fabrication method, provides an optimized platform for a wide range of applications.