Impact of a temporal pulse overlap on laser-tissue-interaction of modern ophthalmic laser systems

Interaction of subsequent laser pulses becomes important relevant with the use of high-repetition rate fs-laser systems for ophthalmic laser surgery. Therefore, we investigated the interaction of temporally separated laser pulses in water by time-resolved photography. With decreasing temporal separation of pulses the probability of laser-induced optical breakdown (LIOB) is firstly diminished by disturbed focusing into persisting gas bubbles. Finally, LIOB is totally impaired by the expanding or collapsing cavitation of the preceding pulse. Hence, laser-tissue interaction might be accompanied by a raised laser energy transmission. In conclusion, these results are of great interest for the prospective optimization of the ophthalmic surgical process with modern fs-lasers.