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In response to the common low sensitivity of fiber Bragg grating (FBG) temperature sensors in measurement, an FBG temperature sensor sensitized in a substrate-type package structure is proposed.

The sensitivity of sensors is analyzed theoretically; aluminum alloys with large coefficient of thermal expansion are used; the ANSYS software is used for simulation analysis and optimization design of sensors; real sensors are developed based on simulation results; in this study, a test system was built to test the performance of the proposed sensor.

The results suggested that the sensitivity of encapsulated FBG temperature sensor is 27.3 pm/°C in the range of −20 °C to 40 °C, which is 2.7 times that of bare FBG sensor, while the linearity is up to more than 0.99.

The sensitivity of FBG temperature sensor is greatly improved by the design of the structure.

This study innovatively proposes substrate-type sensitized FBG temperature sensor. The temperature sensitivity of fiber grating can be improved by single metal structure, and the effect of structural strain can be reduced by a tab structure. The study results provide a reference for the development of like sensors and the further improvement in the sensitivity of FBG temperature sensors.

This study aims to solve the problem of temperature cross sensitivity of fiber Bragg grating in structural health monitoring, proposing a novel acceleration sensor based on strain chirp effect which is insensitive to temperature.

A kind of M-shaped double cantilever beam structure is developed. The fiber grating is pasted in the gradient strain region of the beam, and the chirp effect is produced under the action of non-uniform stress, and then the change of acceleration is converted into the change of reflection bandwidth to demodulate and eliminate the temperature interference. Through theoretical analysis, simulation and experimental verification with rectangular beam sensor.

The results show that the sinusoidal curvature beam sensor is insensitive to the change of temperature and is more likely to produce chirp effect. The sensitivity is about 317 pm/g, and the natural frequency is 56 Hz.

This paper fulfils an insensitive to temperature changes sensor which has effectively solved the temperature cross-sensitivity problem in building structure health monitoring.