Abstract
A compact photonic crystal nanobeam cavity with a ${20}\;\unicode{x00B5}{\rm m} \times {0.8}\;\unicode{x00B5}{\rm m}$ footprint supporting simultaneous air and dielectric resonant modes is proposed for dual-parameter sensing of refractive index and temperature. The structure consists of a row of chirped annular holes and an air-slot etched in an asymmetrical silicon slab. By tapering the lattice period and hole radius, the bands for air and dielectric modes shift in opposite directions, enabling confinement in a single cavity. Numerical simulations determine refractive index sensitivities of 173.59 nm/RIU for the air mode and 286.82 nm/RIU for the dielectric mode. Temperature sensitivities are 69.6 pm/°C and 78.7 pm/°C for the two modes, respectively. The structure demonstrates strong resistance to external interference with refractive index and temperature disturbance resistance coefficients of ${2.3} \times {{10}^{- 5}}$ and 0.07. The high sensitivities in an ultracompact footprint with resistance to crosstalk make this dual-mode nanocavity promising for on-chip biochemical sensing applications.
© 2023 Optica Publishing Group
Full Article | PDF ArticleMore Like This
Zixing Gou, Chao Wang, Zhe Han, Tongyu Nie, and HuiPing Tian
Appl. Opt. 61(16) 4802-4808 (2022)
Tongyu Nie, Zhe Han, Zixing Gou, Chao Wang, and Huiping Tian
Appl. Opt. 61(6) 1552-1558 (2022)
Yongqin Wu, Fujun Sun, Shuo Yang, Zhongyuan Fu, Chao Wang, and Huiping Tian
J. Opt. Soc. Am. B 37(12) 3850-3856 (2020)