Design and fabrication of a grism placed at the end face of an optical fiber for coupling light into a waveguide

In this study, we designed, fabricated, and experimentally tested grating-prism (grism) structures placed at the end face of an optical fiber to couple light into waveguides. We proposed a simple and fast numerical computational approach based on the search conditions of guided-mode resonance to optimize the coupler geometry. Finally, we used the low-cost, repeatable, and accurate nanoimprint method to fabricate an optical fiber end-face grism, which enables the coupling of light into SU-8 waveguides. Moreover, the fabricated fiber coupler was used to estimate waveguide losses.