THE GROWTH DEFECTS IN SELF-FREQUENCY-DOUBLING LASER CRYSTAL NDXY1-XAL3(BO3)(4)

The growth defects in flux-grown NdxY1-xAl3(BO3)(4) (NYAB) single crys tals have been investigated by means of chemical etching and synchrotr on radiation techniques. The band-shaped and polysynthetic twins were detected by optical microscopy due to the difference in etching rates between the host crystal and the twin. In the meantime, the orientatio n and symmetry of the twins were analyzed from their etching patterns. A large number of etch pits with regular shapes were also found on th e surface, and these etch pits correspond to outcrops of the dislocati ons originating from the seed crystal or inclusions.