Step-Etched Prism Coupling for Optical Waveguide Biosensors

摘要

We report a light input coupling method into a buried planar waveguide that is very promising for applications in disposable optical waveguide biosensors. The superstrate of the waveguide is step-etched and a prism made from polystyrene is permanently bonded onto the eteched step using optica lgulde. The plastic prism and the waveguide form a "plug-in" assembly of the diposable part of a biosensor system. For light input coupling, no other pressure sensitive contact of optical components is required and a laser beam simply nedds to be directed at the right positon. Our experimental results show that the coupling has a highly reproducible efficiency of more than 20