MULTIPHOTON EXCITATION OF MN4+ AND CR3+ LUMINESCENCE IN MGO

Multiphoton excitation of the luminescence spectra of Mn4+ and Cr3+ ions has been observed in single crystal MgO. MgO crystals irradiated with pulses from a XeCl laser exhibit a strong 745 nm luminescence band at 293 K. The 670.6 nm vibronic luminescence band of Mn4+ was readily observable at 14 K. The luminescence of the 670.6 nm line shows a six photon dependence on incident XeCl laser intensity, suggesting that the 670.6 nm emission is pumped by energy transfer from excitonioy molecules. Cr3+ emission also shows a multiphoton dependence on excitation intensity. © 1990.