Abstract A sapphire fibre thermal probe with Cr3+ ion-doped end is developed by using the laser heated pedestal growth method. The fluorescence thermal probe offers advantages of compact structure, high performance and ability to withstand high temperature in a detection range from room temperature to 450℃. Based on the fast Fourier transform (FFT), the fluorescence lifetime is obtained from the tangent function of phase angle of the non-zeroth terms in the FFT result. This method has advantages such as quick calculation, high accuracy and immunity to the background noise. This FFT method is compared with other traditional fitting methods, indicating that the standard deviation of the FFT method is about half of that of the Prony method and about 1/6 of that of the log-fit method. And the FFT method is immune to the background noise involved in a signal. So, the FFT method is an excellent way of processing signals. In addition, a phase-lock amplifier can effectively suppress the noise.
Received: 09 October 2005
Revised: 07 February 2006
Accepted manuscript online:
Fund: Project supported by the Natural Science Research Foundation of Education Bureau of Hebei Province, China (Grant No 2001265).
Cite this article:
Wang Yu-Tian (王玉田), Wang Dong-Sheng (王冬生), Ge Wen-Qian (葛文谦), Cui Li-Chao (崔立超) A sapphire fibre thermal probe based on fast Fourier transform and phase-lock loop 2006 Chinese Physics 15 975
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