Development of an optical biosensor device based on grating-assisted guided hybrid-mode excitation

This paper will present a new sensor device based on the simultaneous excitation of (p-polarized) waveguide modes and surface plasmon polaritons forming so-called guided hybrid-modes. These modes offer greater design flexibility and the potential for monolithic integration of the well-established technique of surface plasmon resonance (SPR). The sensor device consists of a metal-coated planar dielectric waveguide with an embossed shallow diffraction coupling grating and a flow cell on top. Various numerical simulations are presented to achieve optimum sensor parameters complemented by experimental checks of the predicted sensor properties. The experimental section includes the preparation of the sensor device together with measurements using different analyte-solutions, which modify the cladding properties of the sensor chip are presented. Measured reflectivity data of the hybrid-mode sensor are reported and compared to theoretical predictions.