Bessel-Gauss laser beam reshaping for high-precision surgical incisions

Lasers are widely used in clinical environments and are essential tools for high-precision tissue ablation and surgical incisions. Achieving the required laser intensity typically involves focusing a Gaussian beam. However, the intrinsic coupling between focal depth and spot size means small incisions require extremely accurate standoff positioning. Bessel-Gauss beams offer an alternative by decoupling these parameters, but to the detriment of varying intensity along the propagation axis. Here, a beam shaping approach is presented that integrates custom optics with an axicon to generate a modified Bessel-Gauss beam, using a 1030 nm, 6 ps laser. The resultant beam exhibits a near-constant intensity over a fixed axial range. Microscale incisions in lamb liver tissue were performed, demonstrating feasibility for surgical applications with a tenfold improvement in depth of focus compared to a Gaussian beam of similar spot size. This low-cost, passive beam shaping technique offers significant potential for enhancing precision and consistency in surgical procedures.