Sensitivity-Enhanced Tilt Sensor Based on Femtosecond Fiber Bragg Grating

Tilt sensors are crucial in intelligent monitoring, enabling precise measurements and analysis of tilt angles. They have found extensive use in different industries, particularly in robotic systems and structural safety, as they serve as instrumental components within artificial intelligence (AI)based frameworks to facilitate real-time adjustments and operational efficiency. However, conventional tilt sensors may not be as accurate due to performance issues, such as electromagnetic interference (EMI) or temperature changes. This paper proposes a tilt sensor utilizing fiber Bragg grating (FBG) technology to overcome these drawbacks. This paper introduces a fiber Bragg grating tilt sensor with an enhancedsensitivity. When the sensor experiences a tilt angle (θ), the mass block induces a gravitational force and bending moment on the cantilever beam, leading to strain. The two FBGs detect the induced strain, hence causing a wavelength shift. The two FBGs are positioned a distance away from the neutral axis in a cantilever-based design to increase the sensitivity of the sensor. The results of the experiments show the sensor's linearity of 99.94% and sensitivity of 107.46 pm/° over a tilting angle range of -30° to 30°. Additionally, femtosecond FBGs exhibit hightemperature stability and ultrafast response, making them ideal for real-time monitoring applications. The proposed FBG tilt sensor is a femtosecond-inscribed FBG that leverages the capability to withstand high-temperature settings.