Mechanisms of femtosecond laser nanoprocessing of biological cells and tissues

We investigated the working mechanisms of femtosecond laser nanoprocessing in biomaterials with oscillator pulses of 80 MHz repetition rate and with amplified pulses of 1 kHz repetition rate. Plasma formation in water, the evolution of the temperature distribution, thermoelastic stress generation, and stress-induced cavitation bubble formation were numerically simulated for NA = 1.3 and the outcome compared to experimental results. A comparison of the thresholds for the various physical effects with experimental parameters enables to assess the working mechanisms of both modalities for cell surgery.