Catheter for sub-surface ablation in biological tissue

The present invention concerns a subsurface laser-induced optical breakdown (LIOB) catheter including a probe assembly for providing at least one optical pulse to a subsurface target biological tissue site; and a waveguide for guiding the at least one optical pulse to the probe assembly. The probe assembly includes at least one optical element configured to redirect the at least one optical pulse, upon reflection at the at least one optical element, from a waveguide propagation direction to the subsurface target biological tissue site, and to shape the at least one optical pulse upon reflection at the at least one optical element to maintain a pulse duration of the at least one optical pulse at the subsurface target biological tissue site.