NOVEL SAPPHIRE FIBER THERMOMETER USING FLUORESCENT DECAY

A novel sapphire fiber thermometer using fluorescent decay is presente d. The thermal probe is simply a sapphire fiber grown from the laser h eated pedestal growth (LHPG) method, with its end doped with Cr3+ ion. The sapphire fiber is coupled with a normal Y-shape silica fiber bund le for signal transmission. Signal processing system for the fluoresce nt lifetime detection is set up. Relationship of the fluorescent lifet ime and intensity with the temperature for the doped sapphire fiber is carefully measured and presented. The thermometer has good thermal re sponse characteristics due to its specific thermal probe structure. Th e coupling efficiency between the fiber probe and the guiding fiber bu ndle is also high and stable. Experimental result shows that the therm ometer has an average temperature resolution of 1 degrees C between 20 and 450 degrees C. (C) 1998 Elsevier Science S.A. All rights reserved .