Coupled mode analysis of integrated optical waveguide array sensors

In this paper, we propose and model an improved integrated optical waveguide array refractive index sensor, using coupled mode theory and the effective index approximation method. These devices can be used in integrated physicochemical sensing applications, by judicious selection of cladding transducer materials that convert variations in chemical composition into changes of refractive index. We demonstrate that a linear array of multiple co-planar waveguides retains the imaging characteristics of current Multimode Interference (MMI) sensors but with improved device footprint (by decreasing the effective beat length of the device), and higher sensitivity, by increasing the active surface area that is critical in enhancing the detection limit in biological and chemical sensors.