Optical Breakdown on Clusters of Gas Nanobubbles in Water; Possible Applications in Laser Ophthalmology

Here we studied the regimes of optical breakdown in water, stimulated by nanosecond and picosecond laser pulses at a wavelength 1064 nm. A distinctive feature our theoretical model, confirmed experiment, is that case develops on heterogeneous centers-clusters gas nanobubbles. To best knowledge, this first study role clusters nanobubbles liquids are transparent to pump radiation. In experiment described paper, it was found when initially degassed water saturated with dissolved air, threshold decreases. model describing phenomenon suggested. This includes development an electron avalanche inside individual nanobubbles, followed coalescence nanobubble cluster. According estimates, regime occurs radiation intensities about 106–107 W/cm2. It important such low flash (the basic endpoint breakdown) does not appear due deficit input energy. We provide experimental proof regime, pulse range. The good agreement estimates. Since mode very intensities, its excitation result mechanical side effects eye tissues, i.e., shock wave should be excited. Note always during breakdown, which traditionally excited 1012 generation also observed. Since, according estimates given article, volume number density intraocular fluid can reach 108 cm−3, used ophthalmic surgery, as iridotomy.