Spectroscopic properties of stoichiometric Sr3Tb2(BO3)4 crystal as a potential yellow laser medium

Study of the Optical Features of Tb3+:CaYAlO4 and Tb3+/Pr3+:CaYAlO4 Crystals for Visible Laser Applications

“…The emission cross-sections of the 5 D 4 → 7 F 4 transition for Tb 3+ :CYA were calculated to be 0.44 × 10 −22 cm 2 (π) and 0.34 × 10 −22 cm 2 (σ), while the results for Tb 3+ /Pr 3+ :CYA were determined to be 0.35 × 10 −22 cm 2 (π) and 0.21 × 10 −22 cm 2 (σ). The maximum emission cross-section of Tb 3+ :CYA at 587 nm (0.44 × 10 −22 cm 2 ) was of the same order of magnitude as that of Tb 3+ :STB crystal (0.61 × 10 −22 cm 2 E//Z) [13]. In order to explore effects of the doping concentration ratio of Tb 3+ and Pr 3+ on the energy transfer process between those two ions, we produced 10at.% Tb 3+ /0.6at.% Pr 3+ , 10at.% Tb 3+ /1at.% Pr 3+ , and 10at.% Tb 3+ /3at.% Pr 3+ co-doped CYA single-crystal fibers through the micro-pulling-down method.…”

“…The π and σ polarization absorption cross-sections of Tb 3+ /Pr 3+ :CYA at 492 nm and 489 nm were 5.23 × 10 −22 cm 2 and 4.04 × 10 −22 cm 2 , respectively, which are much larger than that of Tb 3+ :CYA. The full widths at half-maximum (FWHMs) of the Tb 3+ :CYA crystal around 487 nm were measured to be 9.39 nm and 8.93 nm for σ and π polarization, respectively, which are larger than the values for Sr 3 Tb 2 (BO 3 ) 4 (8.5 nm at 486 nm) and Tb 3+ :YAlO 3 (3.64 nm at 486 nm) [13,20]. The absorption crosssections were strengthened, meaning that the co-doped Pr 3+ could be used to solve the problem of the weak absorption cross-section of the 7 F 6 → 5 D 4 transition in Tb 3+ .…”

“…As is widely known, based on the energy level of Tb 3+ , the emission bands around 546 nm and 578 nm are located in the green and yellow ranges, respectively, corresponding to the 5 D 4 → 7 F J (5,4) transition [13]. According to previous investigations, Tb 3+ was introduced to some fluoride host materials, such as CaF 2 , CdF 2 , and LiYF 4 [14][15][16], which commonly suffer much energy waste and poor physical and chemical properties.…”