Irreversible modification of transparent dielectrics without plasma formation under femtosecond pulses

The goal of the present research was a study of the accumulation effect in transparent glasses and crystals under multishot irradiation by femtosecond pulses. The laser damage durability of optical components is important in the case of femtosecond pulses because of their wide application with high repetition rates for material treatments. It is concluded that, we have found existence of "cold" damage before plasma formation is reached.