光纤高温传感器是一种利用高温单晶光纤作光纤传感头进行辐射测温和控制的新型传感器。在恶劣环境下 ,单晶光纤的表面完整性易受到破坏 ,影响光纤的传输性能 ,必须对光纤采取一定的保护措施。本文介绍了用溶胶 -凝胶法对蓝宝石单晶光纤涂覆透明多晶氧化铝包层的研究背景 ,制作原理 ,实验过程和结果分析。 Fiber temperature sensor is a high-temperature single-crystal fiber optical fiber sensing head temperature measurement and control of the new radiation sensor. In harsh environment, the surface integrity of single crystal fiber is vulnerable to damage, affecting the transmission performance of optical fiber, the optical fiber must take some protective measures. This paper introduces the research background, fabrication principle, experimental process and result analysis of the sapphire single crystal coated with transparent polycrystalline alumina by sol-gel method.