title: Conical reflection of light during free-space coupling into a symmetrical metal-cladding waveguide.
abstract: Novel conical reflection of light by a thick three-layered metal-clad optical waveguide is observed. A symmetrical metal-cladding optical waveguide is used, which exhibits extraordinary conical reflection during free-space coupling of light to the waveguide. The phenomenon is attributed to the leakage of excited ultrahigh-order guided modes and their inter- and intramode coupling interaction.
authors: Yuanlin
authors: Y
authors: Zheng
authors: Zhuangqi
authors: Z
authors: Cao
authors: Xianfeng
authors: X
authors: Chen