Analysis of Long Period Gratings in the Gradient Structures of Planar Waveguides

This paper introduces the application possibilities of long-period waveguide gratings produced in gradient structures of planar waveguides and their possible usage as the detectors of changes in the refractive index. The influence of technological processes and corrugation's parameters on the resonant characteristics and transmission spectrum (obtained by the numerical simulations) of such structures was presented. The influence of changes in the refractive index of the environment on the transmission spectral characteristics was shown. The possibilities of sensor applications of such structures was presented as well. The calculations were performed for two types of gradient waveguides' structures: produced in BK7 glass with the use of $K^+$ ↔ $Na^+$ ion exchange and produced in soda-lime glass with the use of $Ag^+$ ↔ $Na^+$ ion exchange.