Dimensional Analysis of Double-Track Microstructures in a Lithium Niobate Crystal Induced by Ultrashort Laser Pulses

Double-track microstructures were induced in the bulk of a z-cut lithium niobate crystal by 1030 nm 240 fs ultrashort laser pulses with repetition rate 100 kHz at variable pulse energies exceeding critical Kerr self-focusing power. The microstructure topography was characterized atomic force microscopy piezoelectric response mode. spatial positions laser-induced modification regions inside case beam propagation along optical axis can be directly predicted simple analytical expressions under paraxial approximation. A dimensional analysis morphology double-track structures revealed that both their length and width exhibit monotonous increase energy. presented results have important implications for direct writing technology crystalline dielectric birefringent materials, paving way to control high resolution means effective energy deposition modified regions.