Wearable multifunctional optical sensor based on Er/Yb co-doped GdO nanoparticles and tapered U-shaped fiber.

Wearable sensors with multiple functions are attracting significant attention due to their broad applications in health monitoring and human-computer interaction. Despite significant progress in wearable sensors, it is a significant challenge to monitor temperature and stress simultaneously with a single sensor. A wearable multifunctional optical sensor based on Er/Yb co-doped GdO nanoparticles and a tapered U-shaped fiber is proposed to monitor both temperature and stress in this paper.