120 nm resolution and 55 nm structure size in STED-lithography

Richard Wollhofen, Jaroslaw Jacak, Julia Katzmann, Calin Hrelescu, Thomas Klar

Research output: Contribution to journalArticlepeer-review

162 Citations (Scopus)


Two-photon direct laser writing (DLW) lithography is limited in the achievable structure size as well as in structure resolution. Adding stimulated emission depletion (STED) to DLW allowed overcoming both restrictions. We now push both to new limits. Using visible light for two-photon DLW (780 nm) and STED (532 nm), we obtain lateral structure sizes of 55 nm, a Sparrow limit of around 100 nm and we present two clearly separated lines spaced only 120 nm apart. The photo-resist used in these experiments is a mixture of tri- and tetra-acrylates and 7-Diethylamino-3-thenoylcoumarin as a photo-starter which can be readily quenched via STED.

Original languageEnglish
Pages (from-to)10831-10840
Number of pages10
JournalOptics Express
Issue number9
Publication statusPublished - 6 May 2013


  • Equipment Design
  • Equipment Failure Analysis
  • Lasers
  • Molecular Imprinting/methods
  • Photography/methods
  • Refractometry/instrumentation


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