Near-infrared-to-visible photon upconversion process induced by exchange interactions in Yb3+-doped RbMnCl3
Abstract
Crystals of RbMnCl3 doped with Yb3+ exhibit a strong orange luminescence under near-infrared Yb3+ excitation at 10 K. The broad emission band extending from 17 200 cm-1 to 13 000 cm-1 is identified as a 4T1-->6A1 transition on Mn2+. Of the two inequivalent Yb3+ sites identified by site-selective high-resolution spectroscopy, only one is able to induce efficient upconversion. Excitation with 10-ns pulses indicates that no energy transfer is involved, and the upconversion process consists of a sequence of ground-state absorption and excited-state absorption steps. One- and two-color excitation spectra confirm the occurrence of these two steps. The efficiency of the upconversion process at 10 K and for an excitation power of 200 mW focused by a 53-mm lens is 2 percent. An upconversion mechanism based on exchange interactions between the Yb3+ and Mn2+ ions is proposed to account for the observed behavior.
- Publication:
-
Physical Review B
- Pub Date:
- April 2001
- DOI:
- 10.1103/PhysRevB.63.165102
- Bibcode:
- 2001PhRvB..63p5102V
- Keywords:
-
- 78.55.Hx;
- 75.30.Et;
- 78.47.+p;
- Other solid inorganic materials;
- Exchange and superexchange interactions;
- Time-resolved optical spectroscopies and other ultrafast optical measurements in condensed matter