High-pressure laser spectroscopy ofCr3+:Gd3

Abstract

We report on the effect of high pressure on the room-temperature emission spectra and lifetimes of Cr +:GSGG (Gd3SC2Ga30») and Cr:GGG (Gd3Ga50»). In both systems we observed a dramatic change of the overall emission band shape upon increasing pressure, from a nearly structureless broadband ( T2~A 2 ) to a highly structured narrow band ( E~A 2 )~From the peak energy of the broadband emission, we estimated the pressure-induced blueshift of the T2~A2 transition to be 10 (+2) cm '/kbar. High-resolution measurements in the R-line region ( -700 nm) revealed that the E -+ A2 transition hardly shifts at low pressures ( &40 kbar), whereas at higher pressures ()60 kbar) a nearly linear redshift of 0.65 (+0.05) cm /kbar is observed. Besides pressure-induced spectral changes, an enormous increase in the emission lifetime with increasing pressure was found for both systems. In the case of Cr +:GSGG, the lifetime changed from 110 ps at ambient pressure to 4.4 ms at 125 kbar. For Cr'+:GGG, the lifetime increased from 168 ps to 7.3 ms for the same pressure range. The pressureinduced spectral and lifetime changes are described by a single configurational coordinate model that considers the effect of pressure on the thermal and spin-orbit coupling of the E and T2 states. A previously reported pressure-induced R-line-shift reversal in Cr +:GSGG and the effect of high pressure on the lifetime in Cr +: YAG are also discussed within the same framework.

The effect of pressure on luminescence properties of Cr3+ ions in LiSc(WO4)2 crystals—Part I: Pressure dependent emission lineshape

“…Pressure-induced electronic crossovers in Cr 3+ systems have been observed previously by us [18,21,23,27,29], and others [30,31] in many Cr 3+ -doped systems.…”

Local compressibilities around the substitutional impurities Cr3+ and Fe3+ in MgO crystals

“…For Cr 3+ in the octahedral clusters of crystals, when the energy separation between the 2 E and 4 T 2 states is large (i.e., DE ¼ jEð 4 T 2 Þ À Eð 2 EÞj > 1000 cm À1 , for MgO:Cr 3+ , Eð 2 EÞE14; 320 cm À1 [19] , it belongs to the case ), the R-line emission closely approximates the emission from a pure 2 E level [7,20,21] (not perturbed by the spin-orbit coupling). The pure 2 E level can be calculated by diagonalizing the 4 Â 4 2 E energy matrix [21].…”

Time-resolved spectroscopy in LiCaAlF6 doped with Cr3+ as a function of pressure and temperature

“…Besides applications as tunable solid-state lasers and photoluminescence (PL) materials [1,2], fluoroelpasolites [3], garnets [4] and niobates [5,6] are attractive host materials for Cr 3+ to investigate excited-state crossover (ESCO) processes since they provide crystal-field (CF) strengths, which are close to the 2 E2 4 T 2 crossing point ( Fig. 1(b)).…”

“…Aside the rich fine structure associated with the vibrational coupling and the Fano antiresonance shown by the first excited state4 T 2 ARTICLE IN PRESS www.elsevier.com/locate/jlumin 0022-2313/$ -see front matter r 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.jlumin.2007.10.027 (Octahedral symmetry notation), the three absorption bands at 2.03, 2.93 and 4.53 eV, correspond to CF transitions within 3d 3 configuration of Cr 3+ from the 4 A 2ground state to 4 T 2 , 4 T 1 (a) and 4 T 1 (b) excited states, respectively.…”