Investigation of 3D printing compatible THz chemical sensing platform using negative curvature fibers with elliptical cladding elements

Abstract

In this study, a 3D printing compatible THz chemical sensing platform using negative curvature fibers was numerically investigated. Since the negative curvature design of the fiber allows spectral sensitivity based on the refractive index of the fiber core area, high sensitivities for liquid chemical sensing are observed. The fibers with elliptical tube cladding elements made of UV epoxy resin were designed using a finite element based electromagnetic solver to optimize the confinement and material losses, as well as to control polarization-based sensing by asymmetrical placement of tubes. By analyzing both confinement and material losses for different cladding structures, high sensitivities (>98%) for the detection of ethanol and benzene at an operational frequency of 1 THz are achieved. In order to calculate sensitivity values, the power fraction between the core and cladding areas were computed, and dispersion coefficients were also analyzed in the designed fibers. Using a UV resin-based 3D printer, the designs with a core diameter of 3 mm and tube thicknesses of 0.1 mm were fabricated, and the feasibility of using 3D printing was investigated using image analysis. Overall, the optimized negative curvature fiber design with elliptical cladding elements allowed improved sensitivities for chemical sensing applications. The use of 3D printing technology offers potential for cost-effective and efficient fabrication of THz chemical sensing platforms.