By introducing photonic crystals with Dirac point based on valley edge states,we design heterostructure waveguides on the silicon-on-insulator platform,promising waveguides with different widths to operate in the sing...By introducing photonic crystals with Dirac point based on valley edge states,we design heterostructure waveguides on the silicon-on-insulator platform,promising waveguides with different widths to operate in the singlemode state.Benefiting from the unidirectional transmission and backscattering-immunity characteristics enabled by the topological property,there is no scattering loss induced by the mode-mismatch at the transition junction between the waveguides with different widths.Therefore,the valley-locked heterostructure waveguide possesses unique width degrees of freedom.We demonstrate it by designing and fabricating waveguides with expanding,shrinking,and Z-type configurations.Thanks to the free transition between waveguides with different widths,an interesting energy convergency is observed,which is represented from the imaging of the enhanced thirdharmonic generation of the silicon slab.Consequently,these heterostructure waveguides can be more flexibly integrated with existing on-chip devices and have the potential for high-capacity energy transmission,energy concentration,and field enhancement.展开更多
基金National Key Research and Development Program of China(2022YFA1404800)National Natural Science Foundation of China(62305270,12374359,62375225)+2 种基金Shaanxi Fundamental Science Research Project for Mathematics and Physics(22JSY004,22JSQ039)Xi’an Science and Technology Plan Project(2023JH-ZCGJ-0023)Key R&D Program of Shaanxi Province(2023-JC-YB-502).
文摘By introducing photonic crystals with Dirac point based on valley edge states,we design heterostructure waveguides on the silicon-on-insulator platform,promising waveguides with different widths to operate in the singlemode state.Benefiting from the unidirectional transmission and backscattering-immunity characteristics enabled by the topological property,there is no scattering loss induced by the mode-mismatch at the transition junction between the waveguides with different widths.Therefore,the valley-locked heterostructure waveguide possesses unique width degrees of freedom.We demonstrate it by designing and fabricating waveguides with expanding,shrinking,and Z-type configurations.Thanks to the free transition between waveguides with different widths,an interesting energy convergency is observed,which is represented from the imaging of the enhanced thirdharmonic generation of the silicon slab.Consequently,these heterostructure waveguides can be more flexibly integrated with existing on-chip devices and have the potential for high-capacity energy transmission,energy concentration,and field enhancement.
