title: Highly indistinguishable photons from deterministic quantum-dot microlenses utilizing three-dimensional in situ electron-beam lithography.
abstract: The success of advanced quantum communication relies crucially on non-classical light sources emitting single indistinguishable photons at high flux rates and purity. We report on deterministically fabricated microlenses with single quantum dots inside which fulfil these requirements in a flexible and robust quantum device approach. In our concept we combine cathodoluminescence spectroscopy with advanced in situ three-dimensional electron-beam lithography at cryogenic temperatures to pattern monolithic microlenses precisely aligned to pre-selected single quantum dots above a distributed Bragg reflector. We demonstrate that the resulting deterministic quantum-dot microlenses enhance the photon-extraction efficiency to (23±3)%. Furthermore we prove that such microlenses assure close to pure emission of triggered single photons with a high degree of photon indistinguishability up to (80±7)% at saturation. As a unique feature, both single-photon purity and photon indistinguishability are preserved at high excitation power and pulsed excitation, even above saturation of the quantum emitter.
authors.affiliation: Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstraße 36, Berlin D-10623, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Gschrey
authors.affiliation: Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstraße 36, Berlin D-10623, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Thoma
authors.affiliation: Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstraße 36, Berlin D-10623, Germany.
authors.forename: P
authors.identifier: 0000000284785006
authors.initials: P
authors.lastname: Schnauber
authors.affiliation: Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstraße 36, Berlin D-10623, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Seifried
authors.affiliation: Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstraße 36, Berlin D-10623, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Schmidt
authors.affiliation: Zuse-Institut Berlin (ZIB), Takustraße 7, Berlin D-14195, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Wohlfeil
authors.affiliation: Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstraße 36, Berlin D-10623, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Krüger
authors.affiliation: Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstraße 36, Berlin D-10623, Germany.
authors.forename: J-H
authors.initials: JH
authors.lastname: Schulze
authors.affiliation: Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstraße 36, Berlin D-10623, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Heindel
authors.affiliation: Zuse-Institut Berlin (ZIB), Takustraße 7, Berlin D-14195, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Burger
authors.affiliation: Zuse-Institut Berlin (ZIB), Takustraße 7, Berlin D-14195, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Schmidt
authors.affiliation: Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstraße 36, Berlin D-10623, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Strittmatter
authors.affiliation: Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstraße 36, Berlin D-10623, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Rodt
authors.affiliation: Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstraße 36, Berlin D-10623, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Reitzenstein