Thermal Effects on Y2O3:Eu3+ for Fiber Optic Temperature Sensing

Fiber optic methods have gained acceptance in the past several years as non­ intrusive optical techniques of measuring environmental variables, particularly under hostile conditions. Fiber optic temperature sensors are required for many applications which have a large operating range. One way to implement this sensor is to introduce rare earth-doped materials into a fiber showing temperature-dependent optical emission characteristics. The thermal effects on optical emission characteristics of Y2O3:Eu3+ were studied. The thermal broadening and temperature dependence of the lifetime (τ) of the 611.4 nm emission due to the 5D0 ➔ 7F2 transition were studied in detail in the range of 20 to 850° C. τ was found to be independent of temperature from 20 to 600° C, whereas line broadening depends on temperature in this range. From 600 to 850° C, τ was found to decrease with temperature. This was shown to be due to non-radiative multiphonon emission processes. This result can be applied towards high temperature sensing using an optical fiber containing Y2O3:Eu3+ powder.