蓝宝石晶体高温传感器解调方法研究

Research of the demodulation method of the single crystal sapphire high-temperature sensor

为了从蓝宝石晶体高温传感器输出信号中精确解调出温度信息,建立了一套基于离散腔长变换(DGT)的解调系统。从白光偏振干涉原理出发,分析了高斯光源条件下利用DGT解调蓝宝石晶体高温传感器的原理。针对传统傅里叶变换解调数字频率非均匀采样存在误差的缺点,直接对波长均匀采样得到的光谱数据进行DGT,利用DGT幅值谱峰值解调环境温度引起的光程差(OPD)。进而采用加高斯窗法消除光谱仪背景噪声,进一步提高DGT方法的解调精度。在实际的解调系统中对所提出的方法进行了实验,结果表明,在600～1 200℃测温范围,本文方法可以实现温度的精确测量。

In order to accurately demodulate temperature information from the sapphire crystal temperature sensor,a demodulation system based on discrete gap transform （EGT） is established. Based on the principle of white light polarimetric differential interferometry, the demodulation method of the single crystal sapphire high-temperature sensor illuminated by Gauss distributed optic source is demonstrated via DGT. In order to improve the non-uniform sampling digital light frequency error existing in traditional Fourier transform demodulation, the feasibility of measuring optic path difference （OPD） is presented by directly applying a EGT algorithm to the data sampled at equal optical wavelength interval and using the relation between OPD caused by temperature and the peak amplitude of DGT. The demodulation precision is improved by suppressing the background spectrum noise with the Gauss window. With the help of the demodulating system, the experimental results show that the method can be used for precise high temperature measurement within 600-- 1200 ℃.