OPTICAL NONLINEARITY IN FUSED-SILICA BY PROTON IMPLANTATION

Optical nonlinearity was induced in fused silica through proton implan tation. Average chi((2)) of the order of 1.0 pm/V were induced in low- water fused silica, with isolated regions exhibiting chi((2)) as high as 1.6 pm/V. A minimum dosage of 0.25-0.5 mC was found to be effective in generating the second harmonic in fused silica. A minimum irradiat ion time of 10-15 s was found to be necessary to set up the space-char ge region adequately. Finally, the predominant type of microscopic lat tice damage associated with proton-bombarded fused silicas was found t o be the silicon E' defect site. (C) 1996 Optical Society of America