Defect Study of Tm:YAG Crystal

Tm:YAG crystal with high quality was grown by the Czochralski method. Some of the samples were annealed at 1000 ℃ for 25h in the air. Chemical corrosion was used to the slices of Tm:YAG crystal before and after air annealing. The etch pits in (111) plane were observed by Leitz optical microscope and scanning electron microscope (SEM). The shapes of etch pits located in (111) plane exhibit as a triangle structure. Stress birefringence of Tm:YAG slices as grown and after air annealing was investigated by polarization microscope. The lattice integrality of Tm:YAG crystal was investigated by high-resolution X-ray diffraction. The air annealing on slices for long time in high temperature can reduce the total density of the dislocations, and improve the quality of the crystals.