Pitch-dependent Bragg tuning in corrugated nanowires

Sub-wavelength variations in the diameter of semiconductor nanowires (NWs) produce an effective refractive index contrast for Bragg reflection. Therefore, distributed Bragg reflectors (DBRs) composed of NWs with sidewall corrugations offer a viable alternative to conventional heterostructure-based DBRs. In the present study, finite-element simulations are used to investigate the impact of corrugation geometry and various NW array parameters, including corrugation depth, period, and array pitch, on reflectance spectra and supported optical modes. In particular, pitch-dependent refractive index tuning through interwire near-field coupling significantly influences Bragg mode selection. Single-material, corrugated NWs are a robust and tunable DBR structure suitable for advanced nanoscale optoelectronic applications.