A temperature sensor based on tapered few mode fiber long-period grating induced by CO2 laser and fusion tapering

•A temperature sensor based on tapered FMF-LPG is proposed.•The tapered FMF-LPG is induced by CO2 laser and fusion tapering.•The influence of the grating period on the resonant wavelength is discussed.•The transmission spectrum with different temperature is analyzed.•The temperature sensitivity can reach −0.0393 nm/°C in 30–90 °C. A temperature sensor based on tapered few mode fiber long-period grating is proposed, which is induced by CO2 laser and fusion tapering. Based on the coupling of LP01 and LP11 modes in few mode fiber, the influence of the grating period on resonant wavelength is discussed, and the relationship between the ambient temperature and resonant wavelength shift is analyzed. The temperature measurement experiments of this sensor is performed. The experimental results shows that the temperature sensitivity can reach −0.0393 nm/°C in the range of 30–90 °C. Therefore, the sensor can be applied to temperature measurement in different environments due to its compact structure, small size and easy fabrication.