Theoretical modeling and simulation of fiber Bragg grating sensor interrogator based on linear variable filter

With the increasing frequency of aviation accidents in recent years, aircraft safety has received increasing attention. Aircraft operating condition detection is an important part of aviation safety. Fiber Bragg grating (FBG) sensors, with their excellent characteristics, enable online monitoring of aircraft operating conditions. However, the application of FBG sensors in aviation is currently limited because it is difficult for FBG sensor interrogators to meet the requirements of small size, light weight, and good vibration resistance in the aviation field. Therefore, this paper proposes a linear variable filter (LVF)-based FBG sensor interrogator to meet the requirements. An optical model of the interrogator is established. The parameters which determine the performances of the interrogator are analyzed and the design criteria are discussed. According to the requirements in the aviation field, the optical system of the interrogator is designed. The simulation results show that the LVF-based FBG sensor interrogation system has a bandwidth range of 90 nm (1505 nm-1595 nm), a resolution of 2 pm, and a capacity of 15 FBG sensors.