Fano resonances for high performance sensing in an asymmetric resonator based on hybrid graphene/dielectric metasurfaces
Shuhua Cao,
Qi Wang,
Xufeng Gao,
Shijie Zhang,
Ruijin Hong,
Dawei Zhang
Affiliations
Shuhua Cao
Shanghai Key Laboratory of Modern Optical System, Engineering Research Centre of Optical Instrument and System, The Ministry of Education, University of Shanghai for Science and Technology, Shanghai 200093, China
Qi Wang
Shanghai Key Laboratory of Modern Optical System, Engineering Research Centre of Optical Instrument and System, The Ministry of Education, University of Shanghai for Science and Technology, Shanghai 200093, China
Xufeng Gao
Shanghai Key Laboratory of Modern Optical System, Engineering Research Centre of Optical Instrument and System, The Ministry of Education, University of Shanghai for Science and Technology, Shanghai 200093, China
Shijie Zhang
Shanghai Key Laboratory of Modern Optical System, Engineering Research Centre of Optical Instrument and System, The Ministry of Education, University of Shanghai for Science and Technology, Shanghai 200093, China
Ruijin Hong
Shanghai Key Laboratory of Modern Optical System, Engineering Research Centre of Optical Instrument and System, The Ministry of Education, University of Shanghai for Science and Technology, Shanghai 200093, China
Dawei Zhang
Shanghai Key Laboratory of Modern Optical System, Engineering Research Centre of Optical Instrument and System, The Ministry of Education, University of Shanghai for Science and Technology, Shanghai 200093, China
Improving the performance and sensitivity of metallic sensors is challenging because of the Ohmic loss that occurs for traditional metallic materials. In this work, we optimized a refractive index sensor consisting of graphene and a periodic array of asymmetric Si nanorod units. The sensor was formed by etching an asymmetric pair of nanorods and introducing gaps in the dielectric resonant nanostructures. This confined a large portion of electromagnetic energy into nanoscale hot spots within the gaps. The sensitivity of the sensor increased from 430 to 595 nm/RIU, and the figure of merit increased nearly fivefold from 956 to 4577 RIU−1. The results prove that the gapped dielectric metasurface served as an ideal platform for enhancing the interaction between light and the surrounding medium, making it a promising candidate for high-performance optical sensors.
