Printable Bragg gratings for polymer-based temperature sensors

Optical sensors offer important advantages for sensing applications, compared to their electronic counterparts. These include electrical passiveness and insensitivity to electromagnetic interference. Of considerable interest are large two-dimensional arrays of optical sensors, fabricated in polymers using printing techniques. We describe here the design of waveguide-Bragg-grating-based temperature sensors, fabricated by replication technologies. In contrast to silica fibers, thermal sensitivity of polymeric waveguide Bragg gratings is strongly dependent on the chemical and physical material properties. We introduce simulation results for waveguide and grating design and describe major differences between silica-based and polymeric waveguides with respect to their thermal expansion and thermo-optic coefficients. (C) 2014 Published by Elsevier Ltd.