In this study, we propose a novel type of optical fiber measurement method based on a reflective grating panel for lateral displacement. The signal subdivision model with the tangent and cotangent functions is given, and error analysis and processing are studied. The reflective panel is a homemade grating with a periodic variation of its refractive index, which is used to modulate the reflected light intensity. The device consists of a pair of FBGs with different central wavelengths fabricated by femtosecond laser phase mask method and a metal substrate with lever structure. The system structure and. With the development of fiber optical technologies, fiber Bragg grating (FBG) sensors are frequently utilized in structural health monitoring due to their considerable advantages, including fast response, electrical passivity, corrosion resistance, multi-point sensing capability and low-cost. Abstract: With the development of fiber optical technologies, fiber Bragg grating (FBG) sensors are frequently utilized in structural health monitoring due to their considerable advantages, including fast response, electrical passivity, corrosion resistance, multi-point sensing capability and.