d–d Transitions of Fe3+ ions in Fe-doped K2Al2B2O7 crystal

✍ Scribed by Yonggang Wang; R.K. Li

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 469 KB
• Volume: 32
• Category: Article
• ISSN: 0925-3467
• DOI: 10.1016/j.optmat.2010.04.036

✦ Synopsis

Nonlinear optical crystal Fluorescence Absorption d-d Transition a b s t r a c t

Single crystal of K 2 Al 2 B 2 O 7 (KABO) with 6.3% aluminum substituted by iron was grown by top-seeded solution method using KF-B 2 O 3 as flux. Optical transmittance, reflection and photoluminescence spectra of the Fe-doped KABO crystal were investigated by comparing with those of the Fe-free crystal. The absorption and fluorescence bands in the visible and near infrared regions were assigned to d-d transitions of tetrahedrally coordinated Fe 3+ ions. The results of theoretical calculation based on the crystalfield approximation show a good agreement with the observed optical absorption peak positions. These evidences reconfirmed that the Fe 3+ impurity causes the UV absorption in KABO crystal which prevent it from being used as efficient nonlinear optical materials for the fourth harmonic generation of Nd-based lasers.