Fabrication of Mach-Zehnder Polymer Waveguides by a Direct-Drawing Technique Using a Focused Proton Beam

Proton beam writing (PBW) has recently attracted much attention as a next-generation microfabrication technology. This is a direct-drawing technique and does not need any masks to transfer micropatterns to sample surfaces. In our previous work, we demonstrated the first single-mode straight-line and Y-junction PMMA-based waveguides fabricated using PBW and working at lambda = 1.55 mu m. In this work, we fabricated the first PMMA-based Mach-Zehnder waveguides for the wavelength utilizing PBW in order to construct thermo-optic switches.