4. Photoablative effect

The photoablative effect, also known as ablative photodecomposition, is based on the use of photons with an energy higher than the binding energy of biological molecules. The photoablative process thus consists in dissociating or breaking up matter and expelling fragments at supersonic speed. Photons with energies of the order of 3 to 5 eV are capable of dissociating peptide bonds or the carbon-carbon bonds of poplypeptide chains. This is why UV-emitting lasers such as excimer lasers (ArF: 193 nm-6.4 eV or XeCL: 308 nm-4 eV) or a frequency-quadrupled Nd:YAG laser (266 nm-4.7 eV) are well suited to photoablation.

This effect is particularly used in ophthalmology for refractive surgery on the cornea, where it is possible to correct myopia, mild to moderate astigmatism and small hyperopia. The LASIK (Laser Assisted In-situ Keratomileusis) technique has gradually replaced...