H. Furuya et al., Alleviation of photoinduced damage in GdxY1-xCa4O(BO3)(3) at elevated crystal temperature for noncritically phase-matched 355-nm generation, OPTICS LETT, 25(21), 2000, pp. 1588-1590
We developed a GdxY1-xCa4O(BO3)(3) (GdYCOB) crystal for control of optical
birefringence. GdYCOB crystals were successfully used to generate noncritic
al phase-matched (NCPM) second and third harmonics of 1064-nm lights. Howev
er, we observed degradation of third-harmonic-generation (THG) output power
and distortion of the beam pattern as a result of photoinduced damage and
thermal dephasing. The photoinduced damage was classified into two types. O
ne was gray-track and the other was photorefractive damage. It seems that t
hese types of damage were similar to the types of damage that occurred with
KTiOPO4 and LiNbO3 crystals. We tried to circumvent this problem by crysta
l heating. Photoinduced damage of GdYCOB was overcome by elevation of the c
rystal temperature, and NCPM THG (355-nm) output power from heated GdYCOB i
ncreased to 9 mW (62.5 kHz). (C) 2000 Optical Society of America OCIS codes
: 190.4400, 190.2620, 190.4330, 140.3660.