Authors:
Karsten Ko¨nig
Aisada Uchugonova
Martin Straub
Huijing Zhang
Martin Licht
Department of Biophotonics and Laser Technology, Faculty of Physics and Mechatronics, Saarland University, D-66123 Saarbru¨cken, Germany

Maziar Afshar
Dara Feili
Helmut Seidel
Department of Micromechanics, Microfluidics and Microactorics, Faculty of Physics and Mechatronics, Saarland University, D-66123 Saarbru¨cken, Germany

Low mean powers of 1–10 mW are sufficient for material nanoprocessing when using femtosecond laser microscopes. In particular, near infrared 12 fs laser pulses at peak TW/cm² intensities, picojoule pulse energies, and 85 MHz repetition rate have been employed. Three-dimensional two-photon lithography as well as direct multiphoton ablation have been performed. Subwavelength sub-100 nm cuts have been realized in photoresists, silicon wafers, glass, polymers, metals, and biological targets. When reducing the mean power to the microwatt range, nondestructive two-photon imaging was performed with the same setup taking advantage of the broad laser emission spectrum. Multiphoton microscopes based on low-cost ultracompact sub-20 fs laser sources may become novel nonlinear optical tools for highly precise nanoprocessing and two-photon imaging.