A monolithic PDMS waveguide system fabricated using soft-lithography techniques

A monolithic waveguide system using poly(dimethyl siloxane) (PDMS) was designed, fabricated, and characterized. The waveguide demonstrated good confinement of light and relatively low attenuation at 0.40 dB/cm. The robustness and handling properties of the completed waveguides were excellent, and the process yield exceeded 96%. The waveguide did exhibit moderate temperature and humidity sensitivity but no temporal variation, and insertion loss remained stable over extended periods of time. Applications of this waveguide system in microscale sensing are immense, judging by the frequency of use of PDMS as the substrate for microfluidic and biomedical systems. The monolithic nature of the waveguides also reduces their cost and allows integration of optical pathways into existing PDMS-based microsystems.