蓝宝石激光晶体高温传感方法研究

High temperature sensing technology is in great demand in aerospace, aircraft and energy industries, traditional technologies have short-service-life and high -consumption sensors for its low corrosion resistance material in high temperature. Since sapphire has advantages of a high temperature resistance, corrosion resistance, good stability, sapphire fiber high temperature sensing technologies received wide attention, but the disadvantages including low SNR and fabrication difficulty limit their development. This project proposed sapphire crystal doped laser temperature sensing method, measuring the laser emission wavelength laser crystal in high temperature environment to get the measured temperature. With the pump light doped sapphire laser crystals is stimulated to generate laser, due to the microscopic physical properties of laser crystal material including lattice vibration, electronic interaction will be changed by temperature, the stimulated-emission line distribution and laser spectrum line will be affected, which causes that the output laser wavelength is related to the temperature. In this method, signal is laser that is greatly stronger than the F-P sensor’s interference signal and fluorescence signal, which will increase the system SNR and improve the measurement accuracy; secondly, since the wavelength signal be absolute measurement, the measuring results will be less affected by intensity fluctuation or black body radiation noise, which will guarantee measure precision in high temperature area; finally, the temperature probe will be entirely composed of high temperature resistance crystal material, which avoid the influence of high temperature on the probe structural stability and has good long-term reliability.

高温传感是航空航天、能源工业等领域中亟需的技术，传统技术由于在高温下抗腐蚀能力差，传感器的寿命短、消耗大，蓝宝石光纤高温传感技术由于耐高温、耐腐蚀、稳定性好的优势受到广泛关注，但是信号强度弱，信噪比差的问题限制了它的发展。本项目提出蓝宝石掺杂晶体激光高温传感方法，通过测量被测高温环境中激光晶体发射的激光波长，得到所测高温。用泵浦光激发蓝宝石掺杂晶体产生激光，由于温度会改变激光晶体材料的晶格振动、电子相互作用等微观物理性能，从而影响发射谱线的分布和激光的输出，导致输出激光的波长和温度相关。该方法所测的是激光，将大幅度提高信号强度，与F-P传感器产生的干涉信号和荧光信号相比会大大增加系统信噪比，提高测量精度；其次，得到的波长信号是绝对测量，测量结果受光强波动或黑体辐射噪声的影响小，保证高温区域的测量精度；最后，温度探头将完全由耐高温的晶体材料组成，避免高温对探头结构稳定性的影响，长期可靠性好。

本项目首先完成蓝宝石掺杂晶体的谱线热加宽和热位移机理研究，包括温度对蓝宝石掺杂晶体晶格振动和电子的相互作用机制，高温下蓝宝石掺镝、掺铥晶体的发射谱线分布等。然后建立蓝宝石掺杂晶体激光振荡输出运行模型，完成高温环境对蓝宝石掺杂晶体热学性能和蓝宝石微片谐振腔工作机理影响，得到温度调节激光输出波长机制下的激光器设计影响因素。最后完成掺杂晶体设计和蓝宝石微片制备，泵浦光源和光路设计；搭建激光高温探头制备和激光温度传感高温测试平台；完成蓝宝石掺杂晶体激光温度传感方法实验验证。