Towards fabrication and application of polymer based photonics networks and sensors

Highly-functional photonic sensor networks integrated in thin polymer foils offer great potential for versatile applications in the life sciences, medicine, environmental analytics or production technology. For their realization, suitable low-cost and high-throughput production techniques need to be developed. Here, we describe work towards this goal, i.e. the fabrication of multimode polymer waveguides through a combination of thermal imprint and doctor blading. For imprint master stamp fabrication, a combined Bosch and O2 plasma etching process in silicon is utilized. We also demonstrate stamp fabrication by an additive manufacturing method, i.e. by employing maskless UV lithography, to enhance the flexibility and cost-effectiveness of our approach. We, thus, realize various all-polymer waveguide arrays, beam splitters, and grating couplers which serve as basic elements to create more complex photonic circuits. We also demonstrate polymer based transmission lines comprising semiconductor as well as organic light sources and detectors. We discuss both the integration of semiconductor light sources and detectors such as verticalcavity surface-emitting lasers (VCSEL) and photo detectors as well as organic light emitting diodes (OLEDs) and organic photo detectors. In first applications, we combine these elements to create sensor arrays for measuring temperature, strain or refractive index. We show results of various sensor types utilizing different measurement principles implemented in laboratory environments so far. For example, a waveguide array containing a linear discontinuity which serves as elongation zone for displacement, strain or tilt measurement by detecting the intensity variation of the transmitted light propagating inside the structure is presented. In future, we plan to create more powerful sensor photonics networks for reliable and robust applications in real life, e.g. for point-of-care testing or production monitoring.