Growth mechanism of Cr:forsterite laser crystal with high Cr concentration

Recharging processes of Cr ions in Mg2SiO4 and Y3Al5O12 crystals under influence of annealing and γ ‐ irradiation

“…These two kinds of ions can be distinguished by lifetime values, in the µs scale for Cr 4+ and the hundred-ns scale for Cr 5+ . Cr 6+ is only probably observed by an UV absorption broad band between 350 and 400 nm [7].…”

“…7 one can see the same character of changes of the excitation spectrum for 1200 nm emission under influence of γ-irradiation as previously for 900 nm emission. [7]. But formation of tetravalent Cr 4+ ion being related to the O 2-vacancy existing in the crystal may be a critical factor.…”

“…To increase the concentration of tetravalent Cr 4+ in forsterite:Cr, it seems required to apply a high Cr doping content and a high oxygen partial pressure [5]. The formation of tetravalent Cr 4+ is related also to the concentration of an oxygen vacancy existing in the crystallized forsterite:Cr [6,7]. In the paper a set of defect reaction formulas concerning the formation of tetravalent Cr 4+ in forsterite:Cr were established on the basis of the experimental results of growth and annealing.…”

Phase equilibria in the system NaAl(WO4)2–NaCr(WO4)2

“…This stimulated the studies on single crystal materials with broadband emission in the near-infrared region, as tungstates [1][2][3][4], molybdates [5,6], borates [7,8], garnets [9,10], forsterite [11], germanates [12], alexandrite [13], galates [14] and silicates [15,16]. Cr-doped NaAl(WO 4 ) 2 is a potential laser-active medium because of its high absorption, efficient pumping with visible-range semiconductor diode lasers and broad laser emission [2].…”

Preparation of nanosized sodium–aluminum tungstate, NaAl(WO4)2

“…This stimulated the studies on single crystal materials with a broadband emission in the near-infrared region between the different tungstates [1][2][3][4], molybdates [5,6], borates [7,8], garnets [9,10], forsterite [11], germanates [12], different oxides [13,14] alexandrite [15], galates [16], silicates [17,18] and fluorides [19,20]. Cr-doped NaAl(WO 4 ) 2 is a potential laser active media because of high absorption, efficient pumping with the use of visible-range semiconductor diode lasers and broad laser emission [2].…”