Long single-mode waveguides made by imprint patterning for optical interconnects and sensors

Low-loss polymeric optical waveguides were fabricated by UV-nanoimprinting. With this technique the waveguides are directly patterned by imprinting of the UV-curable optical polymer materials, i.e. no etching processes are needed. By properly manufactured imprinting molds, very smooth waveguide surfaces are achieved and the optical loss is dominated by the material attenuation. The advantages of the manufacturing technology include the potential scalability onto large substrate areas and applicability for fabrication on various substrate materials. For instance, printed circuit boards are interesting substrates for high-bit-rate optical interconnection applications requiring long waveguides, and glass and plastic sheets are interesting for sensor applications. The technology also promises for low overall costs, as it is a relatively simple high-throughput replication process. Both ridge-type and inverted-rib-type single-mode waveguides were fabricated using Ormocer hybrid polymer materials having low optical attenuation. Very low loss waveguides were demonstrated by fabrication long waveguides in a spiral shape. The optical attenuation was characterized of 27 cm-long inverted-rib waveguide spirals having 2 μm-wide cores. The measured average attenuation was 0.25 and 0.56 dB/cm at the wavelengths of 638 and 1310 nm, respectively.