Photoluminescence of Bi4Si3O12:Er3+ crystal excited in the commercial laser diode emission region

Abstract The luminescence of Er 3+ ions in Bi 4 Si 3 O 12 has been investigated in the excitation spectral range corresponding to diode pumping (760–840 nm) under continuous wave laser excitation. In addition to the one photon infrared emission ( 4 I 11/2 → 4 I 15/2 ), up-converted luminescence in the green ( 2 H 11/2 , 4 S 3/2 → 4 I 15/2 ) and red ( 4 F 9/2 → 4 I 15/2 ) spectral regions are observed under excitation within the 4 I 9/2 state (795 nm). From a detailed analysis of cw experimental data it is inferred that such up-converted emissions can be attributed to a combination of excited state absorption and energy transfer up-conversion processes.