title: High numerical aperture hybrid optics for two-photon polymerization.
abstract: We report on an immersion hybrid optics specially designed for focusing ultrashort laser pulses into a polymer for direct laser writing via two-photon polymerization. The hybrid optics allows for well-corrected focusing over a large working distance range of 577 μm with a numerical aperture (NA) of 1.33 and low internal dispersion. We combine the concepts of an aplanatic solid immersion lens (ASIL) for achieving a high NA with a diffractive optical element (DOE) for correction of aberrations. To demonstrate the improvements for volume structuring of the polymer, we compare the achievable structure sizes of our optics with a commercially available oil-immersion objective (100x, NA=1.4).
authors.affiliation: Institute of Applied Physics, Friedrich-Schiller-Universitat Jena, Max-Wien-Platz 1, D-07743 Jena, Germany. Frank.Burmeister@iof.fraunhofer.de
authors.forename: Frank
authors.initials: F
authors.lastname: Burmeister
authors.forename: Uwe D
authors.initials: UD
authors.lastname: Zeitner
authors.forename: Stefan
authors.initials: S
authors.lastname: Nolte
authors.forename: Andreas
authors.initials: A
authors.lastname: Tünnermann
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D007909:Lenses; D017785:Photons; D011108:Polymers / Q000737:chemistry* / Q000528:radiation effects
chemical_list: D011108:Polymers