Flexografically printed optical waveguides for complex low-cost optical networks

Flexographic printing enables the rapid production of complex planar optical networks at low costs. Only waveguides without an upper cladding have been fabricated using flexographic printing. In these systems, the waveguide core is guided in contact with air. The Polymer Poly(methyl methacrylate) (PMMA) has been used as the lower cladding in previous systems. In this paper, a process for a flexographically printed waveguide in a complete cladding of UV-curable polymer will be demonstrated for the first time. Straight waveguides with cladding are compared to waveguides with without an upper cladding. Attenuation is determined to be 1.85 dB cm⁻¹ and 2.1 dB cm⁻¹ , respectively. In addition, s-bends are manufactured. For these, the cutoff radius is 22 mm (not cladded) and 30 - 45 mm (cladded). The results show that it is possible to manufacture waveguides suitable for industrial applications flexographically.