J4 ›› 2010, Vol. 27 ›› Issue (3): 270-275.

• Laser Tech. and Devices • Previous Articles     Next Articles

Study on the cracking and defects of Nd:YAG laser crystal

QUAN Ji-liang1,XIE Zhi-wei1,YANG Yuan-zheng1,LI U Liao2, WU Nan-ping2   

  1. 1. Guangdong University of Technology, Guangzhou  510006, China;
    2.Guangzhou Semiconductor Material Academy, Guangzhou  510616, China
  • Published:2010-05-28 Online:2010-05-11

Abstract:

Cracking in Nd:YAG laser crystals grown along <111> by Czochralski method is often observed. The growth defects in the cracked Nd:YAG crystal were studied with optical microscopy, scanning electron microscope(SEM), X-ray diffractometry and optical absorption method. There are a lot of inclusions in cracked crystal, whose composition deviates from the normal composition of crystal. The dislocation density is so high that the phenomenon of pile-up occurs. Some micro-cracks has been observed in dislocations etch pit. Cracking results from stress concentration caused by inclusions, which is caused by components overcooling , fluctuating of growth rate and asymmetry of temperature gradient in later period of crystal growth .

Key words: Nd:YAG crystal∣cracking∣micro crack∣lattice distortion