Calibration of the ruby R 1 and R 2 fluorescence shifts as a function of temperature from 0 to 600 K

Recent work by Gupta and Shen [Appl. Phys Lett. 58, 583 (1991)] has shown that in a nonhydrostatic environment, the frequency of the ruby R2 line provides a reliable measure of the mean stress or pressure. When using the frequency of either the R1 or R2 line to measure pressure at nonambient temperature, it is necessary to know the temperature dependence of the line shift. Unfortunately, the shift of the R2 line with temperature has not been reported. The ruby R1 and R2 fluorescence shifts have been determined as a function of temperature from 15 to 600 K. Both can be fitted very well to the simple cubic forms R1(T) =14 423+4.49×10−2T−4.81×10−4T2+3.71×10−7T3 cm−1 and R2(T)=14 452 +3.00×10−2T−3.88×10−4T2+2.55×10−7T3 cm−1. From 300 to 600 K the shifts fit well to linear functions of temperature. In addition, it is found that the R1-R2 splitting changes by about 3 cm−1 over the 600 K temperature range. Linewidths were found to vary both with temperature and from sample to sample.