Transverse and Axial Resolution of Femtosecond Laser Surgery
Abstract Femtosecond lasers are capable of precise ablation inside transparent media, including glass and in vivo samples. The transverse and axial resolution of damage inside the bulk are important parameters of ablation. The transverse resolution is straightforward to measure, but the axial resolution is much more difficult to measure and rarely performed. Using a 1040-nm, 400-fs pulsed laser, we performed ablation inside glass with a transverse and axial resolution of 0.75 µm. By fitting damage spot measurements to theoretical predictions, we find an ablation threshold of 6.4 x 1012 W/cm2. We also ablated neuron cell bodies and fibers in C. elegans and demonstrate submicrometer resolution in both the transverse and axial directions, consistent with our results in glass. Using simple yet rigorous methods, we define the resolution of laser ablation in transparent media along all directions.