Guided wave sensing of polyelectrolyte multilayers

Abstract

A planar optical waveguide configuration is proposed to monitor the buildup of thick polyelectrolyte multilayers on the surface of the waveguide in aqueous solutions. Instead of detecting the layer by the electromagnetic evanescent field the polyelectrolyte layer acts as an additional waveguiding film that is sensed by guided waves instead of evanescent waves. This leads to a considerably improved sensitivity and dynamic range.