Integrated polymeric interferometer with slot waveguide for photonics sensing

Slot waveguides are becoming more and more attractive optical components, especially for chemical and bio-chemical sensing. Polymeric double slot waveguide for photonics sensor based on integrated Mach-Zehnder interferometer was designed, simulated and studied in this work. The polymeric double slot waveguide was designed on commercial OrmoComp polymer platform and operated at visible 632.8 nm wavelength. Designed polymeric slot waveguide detects the refractive index change of the ambient material by evanescent field label-free techniques. The motivation for the reported work was to design a low-cost polymeric double slot waveguide for sensing arms of integrated Mach-Zehnder interferometer optical sensor with reduced temperature dependency in comparison to silicon photonics platform. The minimal dimensions of double slot waveguide structure were designed for researcher direct laser writing fabrication by nonlinear two-photon polymerization. The normalized effective refractive index changes of TE and TM fundamental modes in polymeric strip, double slot and double slot with high refractive index covering waveguides were compared. The sensitivity of the normalized effective refractive index changes of TE and TM fundamental modes on refractive index changes of the ambient material was investigated by glucose-water solutions.