Temperature Variations of Spectra and Images of Photoluminescence from Heavily Cr-Doped Ruby

Abstract

Photoluminescence (PL) spectra, intensities, and image brightness of 0.1–6.0 at% Cr-doped ruby were investigated across temperatures ranging from 24° to 600 °C. PL emissions at λ = 670, 694, 707, and 715 nm were observed in rubies doped with 0.1–1.0 at% Cr. In rubies with higher doping levels of 1.5–6.0 at% Cr, an additional PL emission at λ = 770 nm was detected. PL intensities at λ = 694, 707, 715, and 770 nm decreased with increasing temperatures from 24° to 600 °C, while the PL intensity at λ = 670 nm showed a similar temperature-dependent decrease. The variation in PL image brightness with temperature, particularly the increase observed from 24° to 200 °C, is predominantly influenced by the PL intensity variations at λ = 670 nm. Decay curves and fluorescence lifetimes of PL from ruby with various Cr concentrations were also evaluated at temperatures RT-200 °C.