Design of nonlinear surface wave guided sensors

Abstract

In recent years, optical wave guided sensors have attracted scientists for the development of biochemical and biomedical optical sensors in addition to optical communicative devices. These sensors show immunity to electromagnetic fields and have no danger of ignition so that they are used in cases of risky environments. Optical sensors have additional advantages: higher sensitivity, higher stability and lower price. Surface sensing, in particular, is used in recognition of adsorption or deposition on a certain surface such as the detection of adsorbed proteins, antibodies and bacteria cells. In this work, a sensing layer (extra ultra-thin film) iss assumed to rest on surface of a thin film covered with a nonlinear clad of lief dependent refractive index. A normalized analysis for the design of evanescent wave sensors is carried out for linear waveguide sensors with normal asymmetry (i.e., substrate refractive index is higher …