UP-CONVERSION LUMINESCENCE OF ER3+ IN CHLORIDE GLASSES BASED ON ZNCL2 OR CDCL2

Upconversion luminescence of Er3+ in the chloride glass system has been investigated in ZnCl2-BaCl2-KCl-ErCl3 and CdCl2-BaCl2-KCl-ErCl3 glasses. Under 800 nm excitation, the glasses gave upconversion luminescence with barely detectable red (around 660 nm), very intense green (around 525-560 nm), and considerably intense blue (around 410 nm) emissions. The intensity of blue emissions was far stronger than that observed for any of other Er3+-doped glass systems, revealing that Er3+-doped chloride glasses can efficiently convert the infrared light into much shorter wavelengths. The green emission is attributed not only to the thermally couple H-2(11/2) and S-4(3/2)-->I-4(15/2) transition but also to the H-2(9/2)-->I-4(13/2) transition. The blue emission is due to the H-2(9/2)-->I-4(15/2) transition. The blue and green upconversion luminescence results from a two-photon process. (C) 1994 American Institute of Physics.