Composite polymeric-inorganic waveguide fabricated by injection molding for biosensing applications

Inorganic based optical transducers have demonstrated their suitability for labelled and label-free sensing of biomolecules but suffer from their relatively high cost. Photonic structures fabricated in polymer by molding techniques could drastically reduce the cost per test and pave the way for label-free screening in point-of care environment where the cost per test is an essential concern. In this paper we present the advances in the fabrication of waveguides with cyclo olefin copolymer (COC) cladding and TiO₂ core with mass-production compatible injection molding and evaporation. We demonstrate the optical propagation in a slab waveguide supporting both transverse electric and magnetic modes and monitor the response of the phase difference between the two modes when a droplet of water is deposited on the chip.