Development of a compact sapphire fiber thermometer probe using fluorescent decay

摘要

Abstract: A new constructed fiber thermometer probe usingfluorescent decay is presented. The fluorescentmaterial in the probe is substituted for by using acompact sapphire fiber, in which the end part is dopedwith some fluorescent dopant. The sapphire fiber iscoupled with the normal silica fiber for signaltransmission. Because the sapphire fiber is of enoughlength, the coupling can be made at a place away fromthe severe environment. Then the performance of theprobe can be assured by the excellent physicalproperties of the sapphire fiber if only the doped endis ideally combined with the fiber itself. The sapphirefiber with Cr$+3$PLU$/ doping in the end was grownusing laser heated pedestal growth (LHPG) apparatus.Two kinds of doping methods were compared to achieve anideally combined sapphire fiber. Using a high brightgreen LED as the stimulating light source, thefluorescence of the fiber with only end doped wasmeasured using an optical multi-channel analyzer. Thefluorescence at the wavelength of 694 nm can be clearlydetected. Temperature dependance of the fluorescentdecay is being determined between the temperature of 20to 450 degrees Celsius, on which the temperature can bemeasured. !5