Laser stimulated bistability in the Yb doped Nd gallate

摘要

An effect similar to the one observed in the case of Nd_3BWO_9:Yb was discovered during investigation of the emission excited at 0.77 um 10 ns pulsed SHG of the Er3+ glass lasers in the Yb doped Nd gallate (NdGaO_3: Yb). The laser beam was used simultaneously for photo thermal heating as well as for the photo excitation. We have discovered an enhancement of the intensities of the Nd~(3+) emission lines (at about 1060 nm) and decrease of the intensity of the Yb~(3+) lines at 975, and 994 nm. The photo treatment of the 2 mm thick samples were performed at temperature about 10 K. Such optically stimulated bistability may be caused by photo thermal mechanisms, and principal role of the IR reflected modes at 450 cm~(-1) is shown. The latter are determined by PL of Nd → Yb transfer or Yb → Nd back transfer processes. The observed phenomenon may be used for production of optically operated switchers. The PL spectrum possesses more complicated structure with respect to other hosts, which may reflect a different local surrounding of the incorporated ions.