Excimer and Nd:YAG laser-based systems incorporating air-cooled fiber-optic probes for turbine engine high-temperature fluorescence intensity imaging and fluorescence decay lifetime thermometry measurements
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- 作者：Sami D. Alaruri ; sami_laser@yahoo.com" class="auth_mail" title="E-mail the corresponding author
- 关键词：Thermographic phosphor ; Fiber-optic endoscope ; Photomultiplier ; CCD camera ; Pixelation effect
- 刊名：Optik - International Journal for Light and Electron Optics
- 出版年：2016
- 出版时间：January 2016
- 年：2016
- 卷：127
- 期：1
- 页码：246-249
- 全文大小：536 K
文摘
In this work, a description for a pulsed Nd:YAG laser-based system operating at 266 nm (generated by passing the 1.064 μm fundamental wavelength through two non-linear KD*P crystals ) for non-contact high-temperature 1-D thermographic phosphors fluorescence intensity and decay lifetime measurements is provided. Also, the article provides a description for a pulsed XeCl excimer laser-based system operating at 308 nm (XeCl) for non-contact high-temperature 2-D thermographic phosphor fluorescence intensity measurements. Both laser systems incorporate air-cooled fiber-optic probes for delivering the excitation laser energy to an engine part coated with thermographic phosphor (Y2O3:Eu or YAG:Tb). Furthermore, the air-cooled probe used with the Nd:YAG laser measurement system incorporates nine 1000 μm core diameter fibers for guiding the emitted fluorescence radiation to the photomultiplier detection system. Whereas, the air-cooled probe used with the excimer laser-based system incorporates a coherent fiber-optic bundle endoscope for imaging the engine parts. The honeycomb pattern (pixelation effect) imposed on images captured by the CCD camera (12 × 13.7 μm pixel size) coupled to the endoscope eyepiece is removed by applying digital high-frequency spatial filter to the image 2-D Fourier transform. Moreover, fluorescence decay lifetime and intensity measurements collected from Y2O3:Eu and YAG:Tb phosphors as a function of temperature are discussed.