Low-cost fabrication of all-polymer components for integrated photonics

For various applications such as optical communication, sensor technology, and optical interconnects, microoptical polymer devices show great promise. Especially, straight and bent optical waveguides as well as beam splitters represent the building blocks of these devices. In this paper, we introduce a novel combination of simple fabrication techniques and cost-efficient polymer materials for the fabrication of planar polymer optical waveguides. We present a low-cost fabrication process through hot embossing and doctor blading techniques and investigate the use of UV curing printing ink and optical adhesive as waveguide core materials with an emphasis on economical fabrication and low optical losses in the near infrared and the visible range of the light spectrum. The refractive indices, the propagation losses and the bend losses of the fabricated waveguides are characterized. We demonstrate propagation losses as low as 0.09 and 0.74 dB/cm for wavelength of 850 and 633 nm, respectively. Furthermore, we investigate the crosstalk between adjacent waveguides as a function of the distance separating them and present an application of the presented fabrication technique in the form of beam splitters. We also investigate beam splitters having spliting ratios of 1:2, 1:4, and 1:8 and demonstrate excess losses per branching region of down to 0.11 dB and high output uniformity. All these experimental values represent important benchmarks, which demonstrate the capability of the presented method to be used for the design of more complex polymer photonic devices.