We studied the onset of induced optical absorption in mono- and polycrystalline Y3Al5O12:Nd3+ samples upon irradiation by a nanosecond electron beam with electron energy of 250 keV and current density of 25 A/cm2. We show that in such crystalline samples, the fast electrons produce induced absorption between 1 and 4.2 eV expressed as a superposition of six adjacent elementary lines. We found that the induced absorption is due to electron transitions from the valence band to a local level around an O−-hole center, while the initial-phase (10−7−10−4 s) relaxation of the induced absorption is determined by quadratic recombination of conduction-band electrons with the O−-hole centers. The higher density of structural defects in the polycrystalline sample than the monocrystalline sample increases the band-electron lifetime against capture by O− centers.
|Number of pages||5|
|Journal||Journal of Optical Technology (A Translation of Opticheskii Zhurnal)|
|Publication status||Published - 1 May 2020|
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Computational Mathematics
- Applied Mathematics