GA based management of strain response in RII-type single mode optical fiber

In this article, the strain behaviour of the depressed inner core triple clad single mode optical fiber is investigated. Both tensile and compressive types of axial strain are considered in simulations. The modal analysis of the fiber structure is based on linear polarization (LP) approximation method. Mode field diameter (MFD) of the fiber is selected as the indirect parameter for strain sensing task and investigating the MFD behaviour of the fiber, the strain sensitivity is augmented through independent adjustment of the structural parameters. Subsequently, a design procedure based on evolutionary genetic algorithm (GA) is introduced for consideration of simultaneous effect of all hyper-parameters of the fiber which yields the strain sensitivity of 15.96 pmμε⁻¹. The substantial sensitivity attained is as the inherence of complicated configuration in multilayer fiber as well as the GA based method. Furthermore, negligible temperature sensitivity of −6.97 × 10⁻⁷ pmC⁻¹ removes the temperature compensation technique which is inevitable stage of fiber optic measurement systems. Additionally, the simulation results admit the stable strain response of the proposed structure.