Dataset 1 Single-mode sapphire fiber temperature sensor

Sapphire fiber can withstand temperatures of around 2000°C, but it is multimoded, giving poor precision sensors. We have demonstrated a single-mode sapphire fiber Bragg grating temperature sensor operating up to 1200°C. A single-mode sapphire fiber was formed by writing a depressed cladding waveguide along the length of a 100-µm diameter sapphire fiber using a femtosecond laser. A second-order Bragg grating sensor was inscribed within the waveguide, achieving a reflectivity of >90% and a narrow bandwidth of

蓝宝石光纤能够承受约2000°C的高温，然而其多模态特性导致其传感器精度不佳。本研究成功演示了一种单模蓝宝石光纤布拉格光栅温度传感器，其工作温度可达1200°C。通过使用飞秒激光在直径为100微米的蓝宝石光纤长度方向上写入压扁的包层波导，形成了单模蓝宝石光纤。在波导内部刻蚀的二级布拉格光栅传感器实现了超过90%的反射率和狭窄的频带宽度。