Gray-track damage in potassium titanyl phosphate under a picosecond regimeat 532 nm

We report studies of gray-track damage formation in flux-grown potassium ti tanyl phosphate exposed to 532 nm, picosecond pulses. We investigate the ti me evolution of damage formation and the evolution of gray-track susceptibi lity as a function of laser intensity. We demonstrate that the energy loss in the crystal is for the most part due to the formation of the centers of absorption. For 26 ps pulses, the intensity damage threshold was found to b e much higher than for nanosecond pulses. Evidence is found that the mechan ism of gray-track formation is nonlinear as a function of intensity and as a function of pulse duration. (C) 2000 American Institute of Physics. [S000 3-6951(00)02934-X].