Regular flux grown RTP has an electric resistivity as low as 108 cm which may exhibit the detrimental electrochromism when subjected to a dc electric field. RTP crystals with high electrical resistivity (~1011-1012•cm) have been grown successfully using our own proprietary technology. The electrochromism is not observed under a continuous 1000V/mm Z-directed electric field over more than 1000 hours. This RTP crystal has high damage threshold large effective electro-optic coefficients and lower half-wave voltage. The Q-switch is built utilizing thermally compensated double-crystal designs.