A Novel U-Shaped and Microchanneled Optical Fiber Temperature Sensor Fabricated by LIGA-Like Process

This paper developed a U-shaped, microchanneled optical fiber temperature sensor based on macrobending-induced whispering gallery mode (WGM). The proposed novel U-shaped, microchanneled optical fiber temperature sensor is fabricated by a LIGA-like process to obtain the microstructure molds on the wafer for the replica molding method. This process can be used for mass production such that the cost of the sensors can be reduced significantly. In temperature sensing experiments, the resonant wavelengths of the WGM sensor exhibited blue shifts as the temperature increased. The temperature sensitivity of the sensor can reach 0.624 nm/°C, with a maximum linearity of 0.994. The results of a system repeatability analysis show a standard deviation of 0.00547 nm/°C in sensitivity following three heating cycles, indicating superior repeatability. Therefore, the WGM temperature sensor possesses superior stability and repeatability.