We report what is to our knowledge the first direct measurement of spatial energy migration among the Tm3+ ions in a Tm,Ho:YAG crystal at room temperature. Four-wave mixing techniques were used to establish and probe transient laser-induced population gratings in the Tm3+ ions. The grating decay rate was measured as a function of the grating spacing. The results show the presence of spatial energy migration among the Tm3+ ions, and the diffusion coefficient of this process was measured to be 4 × 10-7 cm2 s-1 for a sample containing 8.3 × 1020 cm-3 Tm3+ ions.
© 1991 Optical Society of America
Valentina A. French and Richard C. Powell, "Lase-induced grating measurements of energy migration in Tm,Ho:YAG," Opt. Lett. 16, 666-668 (1991)