Investigation of intrinsic and extrinsic defects in solid solution Gd3(Al,Ga)5O12 crystals grown by the Czochralski method

Down- and Upconversion Phenomena in Gd3(Al,Ga)5O12 Crystals Doped with Pr3+ and Yb3+ Ions

“…A mechanism (iii) mentioned above, consisting of indirect excitation of Pr 3+ ions, implies the occurrence of a multiphoton absorption process able to create electrons in the conduction band of the host. The order of this multiphoton excitation (MPE) process is higher as compared to that considered above since the band gap value of GAGG host of 5.93 eV is rather large . Thus, a simultaneous absorption of five photons is needed for incident pulses at 1100 nm and the order of the process increases to 7 for incident pulses at 1500 nm.…”

“…The order of this multiphoton excitation (MPE) process is higher as compared to that considered above since the band gap value of GAGG host of 5.93 eV is rather large. 20 Thus, a simultaneous absorption of five photons is needed for incident pulses at 1100 nm and the order of the process increases to 7 for incident pulses at 1500 nm. Nevertheless, the efficiency of high-order MPE processes that produce free electrons is large enough to counterbalance the self-focusing of femtosecond infrared pulses, providing thereby a stable supercontinuum generation in GAGG host.…”

“…Results presented above indicate that praseodymium ions can enter nonequivalent sites in GAGG host that can be assigned to defects, ligand vacancies, and antisites. It is worth mentioning here that low-temperature absorption spectra of GAGG:Er 3+ point at occurrence of at least two different sites for erbium ions . Results of low-temperature absorption measurement for GAGG:Pr 3+ are gathered in Table .…”

“…Partial substitution of aluminum ions by gallium ions in this host crystal creates a certain structural disorder, resulting in a significant inhomogeneous broadening of spectral lines of incorporated luminescent rare earth ions. 20 It has been demonstrated that rare earth-doped GAGG is able to provide multipurpose materials. When doped with Pr 3+ , it shows scintillating properties with the light yield around 4500 photon/MeV.…”

“…In the present article, we consider down- and upconversion phenomena in Gd 3 Al 2.5 Ga 2.5 O 12 (GAGG) crystals containing Pr 3+ and Yb 3+ ions. Partial substitution of aluminum ions by gallium ions in this host crystal creates a certain structural disorder, resulting in a significant inhomogeneous broadening of spectral lines of incorporated luminescent rare earth ions . It has been demonstrated that rare earth-doped GAGG is able to provide multipurpose materials.…”