Centimeter‐Scale Propagation of Optical Surface Waves at Visible Wavelengths

Abstract Guiding and confining light at interfaces is crucial for applications involving light–matter interactions, such as surface spectroscopy, nonlinear optics, and quantum information technology. While dielectric surface waves offer promising perspectives for strong light confinement at non‐absorbing interfaces, their capacity has not yet been widely explored. This article focuses on the propagation properties of optical modes supported at the free surface of a 1D photonic crystal. The contributions of intrinsic and extrinsic loss mechanisms are investigated. Structures optimized to support long propagating optical surface waves are designed and fabricated. This work experimentally demonstrates, for the first time, the existence of optical surface waves capable of propagating over centimeter‐scale distances in the visible spectral range. The results open new perspectives for the use of optical surface waves in integrated optics and enhanced light–matter interactions.