Executive Summary : | Fiber optics techniques have made significant progress in recent years, particularly in the field of optical fiber sensors for monitoring physical, chemical, and biological characteristics. The bend-induced effect in optical fibers is a significant phenomenon used in structural health monitoring and biomedical applications. These sensors can be used as tilt sensors in civil engineering to monitor subsurface movement and deformation of infrastructures, and in the biomedical field to track the motion of lower back bones, knee joints, and finger joints. Optical fiber bending sensors are primarily based on structures such as interferometers, multi-core optical fiber, plastic optical fiber, fiber Bragg gratings, and photonic crystal fiber (PCF). PCF-based sensors have shown potential in various sensing applications due to their novel optical properties. However, single and dual core PCF have been reported with minimum bending sensitivity, poor repeatability, high cross-sensitivity, and complex fabrications. This proposal proposes exploring a compact curvature sensor based on highly birefringence dual core photonic crystal fiber (PCF) for structural health monitoring and biomedical applications. The project will involve designing a compact highly birefringence dual core photonic crystal fiber (PCF) with a maximum bending sensitivity of 13 nm/(1/m) and a bending range of 0.1 to 3.9 (1/m). An auto encoded dense neural network will be used to optimize the design with less computation time, low mean squared error, and high accuracy. The proposed compact PCF will be fabricated at the University of New south Wales, Australia, and its sensing performances will be analyzed. This analysis will help study the suitability of the proposed compact PCF for advanced biomedical, structural deformation monitoring, robot, and wearable sensors. |