title: Combining in-situ lithography with 3D printed solid immersion lenses for single quantum dot spectroscopy.
abstract: In the current study, we report on the deterministic fabrication of solid immersion lenses (SILs) on lithographically pre-selected semiconductor quantum dots (QDs). We demonstrate the combination of state-of-the-art low-temperature in-situ photolithography and femtosecond 3D direct laser writing. Several QDs are pre-selected with a localization accuracy of less than 2 nm with low-temperature lithography and three-dimensional laser writing is then used to deterministically fabricate hemispherical lenses on top of the quantum emitter with a submicrometric precision. Due to the printed lenses, the QD light extraction efficiency is enhanced by a factor of 2, the pumping laser is focused more, and the signal-to-noise ratio is increased, leading to an improved localization accuracy of the QD to well below 1 nm. Furthermore, modifications of the QD properties, i.e. strain and variation of internal quantum efficiency induced by the printed lenses, are also reported.
authors.affiliation: Institut für Halbleiteroptik und Funktionelle Grenzflächen, Center for Integrated Quantum Science and Technology (IQST) and Research Center SCoPE, University of Stuttgart, Allmandring 3, 70569 Stuttgart, Germany.
authors.forename: Marc
authors.initials: M
authors.lastname: Sartison
authors.affiliation: Institut für Halbleiteroptik und Funktionelle Grenzflächen, Center for Integrated Quantum Science and Technology (IQST) and Research Center SCoPE, University of Stuttgart, Allmandring 3, 70569 Stuttgart, Germany.
authors.forename: Simone Luca
authors.initials: SL
authors.lastname: Portalupi
authors.affiliation: 4th Physics Institute and Research Center SCoPE, University of Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany.
authors.forename: Timo
authors.initials: T
authors.lastname: Gissibl
authors.affiliation: Institut für Halbleiteroptik und Funktionelle Grenzflächen, Center for Integrated Quantum Science and Technology (IQST) and Research Center SCoPE, University of Stuttgart, Allmandring 3, 70569 Stuttgart, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Jetter
authors.affiliation: 4th Physics Institute and Research Center SCoPE, University of Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany.
authors.forename: Harald
authors.initials: H
authors.lastname: Giessen
authors.affiliation: Institut für Halbleiteroptik und Funktionelle Grenzflächen, Center for Integrated Quantum Science and Technology (IQST) and Research Center SCoPE, University of Stuttgart, Allmandring 3, 70569 Stuttgart, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Michler