Precise ablation of soft biological tissue using deep ultraviolet femtosecond laser pulses

In this work, ablation of clinically relevant mammalian brain tissue was demonstrated using 200-fs laser pulses at 205 nm wavelength. The ablated region depth could be controlled by adjusting the pulse energy and pulse spatial separation; using low-energy deep ultraviolet laser pulses allowed for the removal of very fine layers of tissue. Histopathological analysis revealed minimal thermal damage to the tissue regions adjacent to the ablation craters. Optical coherence tomography was used for surface profile measurements of the laser-processed tissue. The presented deep ultraviolet ultrashort laser ablation technique could be utilised in surgical procedures that require precise tissue removal, for example to facilitate more complete resection of tumour margins located close to brain critical structures where use of conventional surgery tools might cause irreparable damage.