Up-conversion emission in violet from yellow in Nd3+: SiO2TiO2-Al2O3, sol-gel glasses

This paper reports an up-conversion emission in violet (408 nm) from Nd3+-d oped 93SiO(2):7TiO(2): 20AlO(1.5) glasses synthesized by the sol-gel proces s. Upon excitation at 583 nm (I-4(9/2)-->(4)G(5/2)), a bright violet up-con version emission at 408 nm has been observed. The behavior of the up-conver sion luminescence has been compared with that of the normal luminescence at both 408 and 1064 nm. The results show that while no concentration quenchi ng for up to 2 mole Nd content is observed for the up-conversion emission, such an effect can be observed for the normal luminescence cases. Although the up-conversion luminescence has a shorter lifetime and weaker intensity, it is of use to the development of sol-gel glass-based waveguide lasers op erating at the violet wavelength. (C) 2000 Elsevier Science Ltd. All rights reserved.