Surface modification of sapphire for enhanced infrared window performance

Two ion implantation conditions were evaluated for improving the mechanical performance of sapphire IR window material. Both increased the average strength as measured by 4-point bend tests and were effective in preventing the propagation of surface flaws. Ion implantation that produced a damaged crystalline surface improved the reliability at lower stresses more than the implantation that produced an amorphous surface. Neither process significantly affected the IR transmission.