Surface plasmon resonance and coloration in stainless steel with a 2D periodic texture

Although stainless steel (STS) is an alloy commonly used in both daily life and the industrial field, little is known about its plasmonic behavior. In this study, we investigated the surface plasmon resonance (SPR) phenomenon in two-dimensionally (2D) textured STS. A 2D periodic grating with a 500 nm pitch was fabricated by imprinting combined with electrochemical etching on the surface of 316L STS plates. Since the fabricated surface texture gave rise to SPR absorption peaks and structural colors, its resonance behavior was characterized in terms of light incident direction and polarization state; the dependence of the SPR wavelengths on these two parameters was theoretically calculated based on the grating-assisted light-coupling mechanism. The experimental results were in good agreement with the theoretical calculations. Grating-coupled SPR can be an effective tool to generate structural colors in STS and may be used in many applications including surface decoration, product identification, and anti-counterfeiting.