In-plane excitation of a topological nanophotonic corner state at telecom wavelengths in a cross-coupled cavity

• DOI: 10.1364/prj.419569
• Publication Date: 2021-05-20T20:00:09Z
• Authors: Xin-Tao He; Meng-Yu Li; Hao-Yang Qiu; Wen-Sheng Ruan; Li-Dan Zhou; Lin Liu; Xiao-Dong Chen; Wen-Jie Chen; Fu-Li Zhao; Jian-Wen Dong
• Keywords: Nanophotonics

In silicon photonics, the cavity mode is a fundamental mechanism to design integrated passive devices for on-chip optical information processing. Recently, corner state in second-order topological photonic crystal (PC) rendered global method achieve an intrinsic mode. It crucial explore such circuits (PICs) under in-plane excitation. Here, we study both theoretically and experimentally nanophotonic silicon-on-insulator PC at telecommunications wavelength. theory, expectation values of mirror-flip operation Bloch modes slab are used characterize phase. Derived from topologically distinct bulk polarizations two types dielectric-vein PCs, induced 90-deg-bend interface, localizing point real space Brillouin zone boundary reciprocal space. To implement excitation experiment, fabricate cross-coupled based on bend interface directly image near 1383 nm using far-field microscope. Finally, by means temporal coupled-mode <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m1"> <mml:mrow> <mml:mi>Q</mml:mi> </mml:mrow> </mml:math> factor (about 8000) retrieved measured transmission spectra. This work gives deterministic guidance potential applications cavity-mode-based PICs, as filters, routers, multiplexers.