Design and Analysis of Nonlinear Optical Waveguide Sensors

Abstract

Recent years have shown increased interest in the investigation of integrated optical sensors [1-4] due to their miniature, high sensitivity, small size, immunity to electromagnetic interference and low price. Biochemical and biomedical sensors are examples of using planar integrated optical wave guide in their structures in both homogenous and surface sensing. In the past few years, there was [5-7] a significant amount of work regarding the applications of lasers and nonlinear optical materials in a large number of opto-electronics devices. The changes of the refractive index in nonlinear media may be used to control the sensitivity of nonlinear wave guide sensors. Abadla, Shabat, and D. Jäger [8, 9] have shifted the study of linear wave guide sensors to nonlinear wave guides sensors. This paper presents our recent works on nonlinear wave guide sensors. Novel nonlinear wave guide sensors are designed for the first time. We derive an extensive theoretical analysis of nonlinear wave guide structure sensors and the conditions for the maximum achievable sensitivity. In homogeneous sensing, the wave guide sensor structure consists of a dielectric film sandwiched between a linear substrate and a nonlinear cladding. An extra very thin layer is added above the film in surface sensing. In both cases, the nonlinear cladding is considered to have an intensity dependent refractive index. Computer programs based on the derived mathematical modeling are developed to analyze the propagation characteristics of various integrated optical nonlinear wave guide structures. The theoretical requirements for reaching high sensitivity of the proposed nonlinear …