Enhanced Terahertz Spectral‐Fingerprint Detection of α‐Lactose Using Sub‐Micrometer‐Gap On‐Chip Waveguides

Abstract We investigate using finite element methods how sub‐micrometer to micrometer‐scale coplanar waveguide (CPW) can be used for the detection of fingerprint spectra very small (of order 10 −14 mL) volumes analytes in terahertz (THz) frequency range. The electric field distribution is investigated near various gap widths between center conductor and ground plane a simulation (ANSYS High Frequency Structure Simulator, HFSS). Taking lactose monohydrate as an exemplar material, Drude–Lorentz model combined its real imaginary permittivities with this numerical simulation, finding significant enhancement width reduced; CPW found increase by factor ≈14 times moving from 20 0.5‐µm‐wide plane, while on‐resonance THz absorption increases times. effective coefficient at 530 GHz function slot block thicknesses understand change confinement overlap incident waves affect coefficient.