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Picosecond optical breakdown: Tissue effects and reduction of collateral damage
Author(s) -
Zysset Beat,
Fujimoto James G.,
Puliafito Carmen A.,
Birngruber Reginald,
Deutsch Thomas F.
Publication year - 1989
Publication title -
lasers in surgery and medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 112
eISSN - 1096-9101
pISSN - 0196-8092
DOI - 10.1002/lsm.1900090302
Subject(s) - picosecond , materials science , irradiation , cell damage , laser , pulse (music) , collateral damage , optics , ultrashort pulse , biophysics , chemistry , biochemistry , physics , criminology , detector , sociology , nuclear physics , biology
Abstract The effects of picosecond laser‐induced optical breakdown on tissue were investigated using high‐intensity 40 ps Nd:YAG laser pulses at 1.06 μm. Tissue damage was evaluated using the corneal endothelium in vitro as a model system. Systematic studies were performed to determine the scaling of the tissue damage and damage range with pulse energy. For suprathreshold lesions, the radius of the damage zone varies as the cube root of the pulse energy, in agreement with simple physical scaling laws. A minimum damage range of less than 100 μm was observed for pulse energies of 8 μJ. Damage morphology was investigated by scanning electron microscopy. Three different damage patterns were observed: cell damage, cell removal, and rupture of Descemet's membrane. Different irradiation geometries were used to study damage mediated by either the shock wave or the cavitation bubble. Comparative studies using 10 ns pulses demonstrated that picosecond pulses yielded a significant reduction in collateral tissue damage.