2022/03/04 by Martin Wegener, Vincent Hahn · 1 voice
Engineering · #Laser Material Processing Techniques #Nanofabrication and Lithography Techniques #Nonlinear Optical Materials Studies
paper · doi:10.1117/12.2604870
openalex publication_date 2022/03/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/29
Two-photon absorption (TPA) 3D laser nanoprinting typically requires femtosecond lasers, which are expensive and bulky. Here, we introduce two-step absorption (TSA) replacing TPA as the nonlinear excitation mechanism. In TSA, the virtual intermediate state in TPA is replaced by a real electronic intermediate state, allowing to use inexpensive continuous-wave lasers. Concerning degenerate TSA, we demonstrate scanning single-focus nanoprinting of state-of-the-art 3D woodpiles with rod spacings down to 300 nm and below, using about 45 µW power from a compact 405 nm semiconductor laser diode. Concerning non-degenerate TSA, we present the status of our work on light-sheet 3D laser projection printing.