Investigation of the Gd Variation of GdxY1-xCa4O(BO3)3 Crystal and Its Application

A nonlinear optical crystal, GdxY1-xCa4O(BO3)3 (GdYCOB), can have its phase-matching properties tuned by changing the compositional parameter x and we reported the noncritical phase matched (NCPM) third harmonic generation (THG) of a Nd:YAG laser. In this paper, detailed compositional analysis was performed to the relationship between the Gd distribution and the crystal growth condition. We also found that GdYCOB with a compositional gradient can compensate the thermal phase-mismatch caused by self-heating. It is the first experimental confirmation of the possibility of neutralization of the thermal dephasing without the crystal cooling for frequency conversion of a Nd:YAG laser.