Optimization of bulk sensitivity for strip, slot, and subwavelength grating-based waveguides for dual-polarization operation

We propose a dual-polarization optimization method for the bulk sensitivity of silicon-on-insulator (SOI) waveguides by defining a multi-objective function that accounts for the substrate leakage losses. The proposed optimization method was used to design micro-ring resonator bulk sensors with strip, slot, subwavelength grating, and subwavelength grating slot waveguides. The subwavelength grating slot waveguide has a bulk sensitivity of 520 nm/RIU and 325 nm/RIU for the TE and TM modes, respectively, both of which are higher than the bulk sensitivities of strip, slot, and subwavelength grating waveguides. Moreover, our Monte Carlo analysis shows that the subwavelength grating slot waveguide has the highest immunity to fabrication errors.(c) 2023 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Automated summary

We propose a dual-polarization optimization method to improve the bulk sensitivity of silicon-on-insulator (SOI) waveguides by considering the substrate leakage losses. This method is applied to design micro-ring resonator bulk sensors with strip, slot, subwavelength grating, and subwavelength grating slot waveguides. The results show that the subwavelength grating slot waveguide has higher bulk sensitivities of 520 nm/RIU for the TE mode and 325 nm/RIU for the TM mode compared to strip, slot, and subwavelength grating waveguides. Furthermore, Monte Carlo analysis demonstrates that the subwavelength grating slot waveguide has the highest immunity to fabrication errors.