Polymeric Strip to Double Slot Waveguide Coupler

Slot waveguides are becoming more and more attractive optical components, especially for chemical and biochemical sensing. The problem of coupling light into the slot waveguides decreases performance of sensor systems with slot waveguide. We report on a design and simulation of polymeric strip to double slot waveguide coupler. The coupler was designed on commercial OrmoComp polymer and operates at a 632.8 nm wavelength. The minimal dimensions of coupler’s parts were designed for researcher direct laser writing fabrication by nonlinear two-photon polymerization. The simulation of the coupler was performed by Finite element and Beam propagation method tools. The overall calculated coupling losses of the designed coupler used in two interfaces strip to double slot and back to strip waveguide are 0.14 dB for TE mode and 0.20 dB for TM mode, respectively.