Benxue Jiang

Study of the effects of Cr ions on Nd in self-Q-switched laser crystal Cr4+,Nd3+:Gd3Ga5O12

In this paper, the absorption and Fluorescence spectra of Cr4+,Nd3+:GGG (Cr,Nd:GGG) crystal, Nd:GGG crystal and Cr4+:GGG crystal are reported. In the absorption spectra there are big absorption bands at 400 and 520nm, which correspond to the 4A2→4T1 and 4A2→4T2 transitions. The luminescent spectra of Cr,Nd:GGG and Nd:GGG show that the luminescent center of Cr,Nd:GGG is at 1.062um, but the intensity is 6 times lower than that of Nd:GGG. The luminescent lifetimes of Cr,Nd:GGG is shorter than that of Nd:GGG. These may be caused by the existence of ground state absorption of Cr4+ which quenches the Nd3+ emission intensity. These Cr,Nd:GGG crystals may be potential materials for compact, efficient, high stability diode- laser-pumped passive Q-switched solid state laser.

Infrared femtosecond laser pulse-induced functional color centers and waveguide in alkali halide crystal

We report on functional color centers and waveguide formed by using 800nm, 120fs, 200kHz pulse laser in alkali halide crystals such as KCl and LiF. These crystals are transparent in the wavelength ranging from 250-1000nm. After irradiated by the 800nm tightly focused femtosecond laser, the crystal changed to dark and color centers have been formed. Some of these color centers are useful and alkali halide crystal with these color centers is one type of laser crystal (color center laser crystal). And also photoinduced refractive index changes have been formed by focusing the laser beam.