A highly sensitive all-fiber temperature sensor based on the enhanced green upconversion luminescence in Lu2MoO6:Er3+/Yb3+ phosphors by co-doping Li+ ions

Great improvement of upconversion luminescence in Lu2MoO6:Er3+/Yb3+ phosphor is observed due to the introduction of Li+ ions and a highly sensitive all-fiber optical temperature measurement platform is established. X-ray diffraction (XRD) results show that pure Lu2MoO6:Er3+/Yb3+ phase has been prepared and Li2CO3 dramatically promotes the growth of Lu2MoO6:Er3+/Yb3+ phase in the scanning electron microscope(SEM) images. In comparison to the sample without Li+ ions, green upconversion luminescence intensity was increased by 516 times. The maximum absolute sensitivity of 0.015 K−1 is achieved at 423 K and temperature measurement error is ±0.8 K. The experimental results lay the foundation for the practical application of the ratiometric all-fiber optical temperature sensor.