AG Optoelektronik und Quantenbauelemente

49 Items

Recent Submissions
Thermal stability of emission from single InGaAs/GaAs quantum dots at the telecom O-band

Holewa, Paweł ; Burakowski, Marek ; Musiał, Anna ; Srocka, Nicole ; Quandt, David ; Strittmatter, André ; Rodt, Sven ; Reitzenstein, Stephan ; Sęk, Grzegorz (2020-12-11)

Single-photon sources are key building blocks in most of the emerging secure telecommunication and quantum information processing schemes. Semiconductor quantum dots (QD) have been proven to be the most prospective candidates. However, their practical use in fiber-based quantum communication depends heavily on the possibility of operation in the telecom bands and at temperatures not requiring e...

Thresholdless Transition to Coherent Emission at Telecom Wavelengths from Coaxial Nanolasers with Excitation Power Dependent β‐Factors

Kreinberg, Sören ; Laiho, Kaisa ; Lohof, Frederik ; Hayenga, William E. ; Holewa, Pawel ; Gies, Christopher ; Khajavikhan, Mercedeh ; Reitzenstein, Stephan (2020-11-08)

The ongoing miniaturization of semiconductor lasers has enabled ultra‐low threshold devices and even provided a path to approach thresholdless lasing with linear input–output characteristics. Such nanoscale lasers have initiated a discourse on the origin of the physical mechanisms involved and their boundaries, such as the required photon number, the importance of optimized light confinement in...

Developing a photonic hardware platform for brain-inspired computing based on 5 × 5 VCSEL arrays

Heuser, Tobias ; Pflüger, Moritz ; Fischer, Ingo ; Lott, James ; Brunner, Daniel ; Reitzenstein, Stephan (2020-08-25)

Brain-inspired computing concepts like artificial neural networks have become promising alternatives to classical von Neumann computer architectures. Photonic neural networks target the realizations of neurons, network connections and potentially learning in photonic substrates. Here, we report the development of a nanophotonic hardware platform of fast and energy-efficient photonic neurons via...

Tools for the performance optimization of single-photon quantum key distribution

Kupko, Timm ; Helversen, Martin von ; Rickert, Lucas ; Schulze, Jan-Hindrik ; Strittmatter, André ; Gschrey, Manuel ; Rodt, Sven ; Reitzenstein, Stephan ; Heindel, Tobias (2020-03-24)

Quantum light sources emitting triggered single photons or entangled photon pairs have the potential to boost the performance of quantum key distribution (QKD) systems. Proof-of-principle experiments affirmed these prospects, but further efforts are necessary to push this field beyond its current status. In this work, we show that temporal filtering of single-photon pulses enables a performance...

A bright triggered twin-photon source in the solid state

Heindel, Tobias ; Thoma, Alexander ; Helversen, Martin von ; Schmidt, Marco ; Schlehahn, Alexander ; Gschrey, Manuel ; Schnauber, Peter ; Schulze, Jan-Hindrik ; Strittmatter, André ; Beyer, Jörn ; Rodt, Swen ; Carmele, Alexander ; Knorr, Andreas ; Reitzenstein, Stephan (2017-04-03)

A non-classical light source emitting pairs of identical photons represents a versatile resource of interdisciplinary importance with applications in quantum optics and quantum biology. To date, photon twins have mostly been generated using parametric downconversion sources, relying on Poissonian number distributions, or atoms, exhibiting low emission rates. Here we propose and experimentally d...

Bright single-photon sources based on anti-reflection coated deterministic quantum dot microlenses

Schnauber, Peter ; Thoma, Alexander ; Heine, Christoph V. ; Schlehahn, Alexander ; Gantz, Liron ; Gschrey, Manuel ; Schmidt, Ronny ; Hopfmann, Caspar ; Wohlfeil, Benjamin ; Schulze, Jan-Hindrick ; Strittmatter, André ; Heindel, Tobias ; Rodt, Sven ; Woggon, Ulrike ; Gershoni, David ; Reitzenstein, Stephan (2015-12-25)

We report on enhancing the photon-extraction efficiency (PEE) of deterministic quantum dot (QD) microlenses via anti-reflection (AR) coating. The AR-coating deposited on top of the curved microlens surface is composed of a thin layer of Ta2O5, and is found to effectively reduce back-reflection of light at the semiconductor-vacuum interface. A statistical analysis of spectroscopic data reveals, ...

Deterministically fabricated quantum dot single-photon source emitting indistinguishable photons in the telecom O-band

Srocka, N. ; Mrowiński, P. ; Große, J. ; Helversen, M. von ; Heindel, Tobias ; Rodt, Sven ; Reitzenstein, Stephan (2020-06-09)

In this work, we develop and study single-photon sources based on InGaAs quantum dots (QDs) emitting in the telecom O-band. Quantum devices are fabricated using in situ electron beam lithography in combination with thermocompression bonding to realize a backside gold mirror. Our structures are based on InGaAs/GaAs heterostructures, where the QD emission is redshifted toward the telecom O-band a...

Deterministically fabricated strain-tunable quantum dot single-photon sources emitting in the telecom O-band

Srocka, N. ; Mrowiński, P. ; Große, J. ; Schmidt, M. ; Rodt, Sven ; Reitzenstein, Stephan (2020-12-01)

Most quantum communication schemes aim at the long-distance transmission of quantum information. In the quantum repeater concept, the transmission line is subdivided into shorter links interconnected by entanglement distribution via Bell-state measurements to overcome inherent channel losses. This concept requires on-demand single-photon sources with a high degree of multi-photon suppression an...

CSAR 62 as negative-tone resist for high-contrast e-beam lithography at temperatures between 4 K and room temperature

Kaganskiy, Arsenty ; Heuser, Tobias ; Schmidt, Ronny ; Rodt, Sven ; Reitzenstein, Stephan (2016-11-29)

The temperature dependence of the electron-beam sensitive resist CSAR 62 is investigated in its negative-tone regime. The writing temperatures span a wide range from 4 K to room temperature with the focus on the liquid helium temperature regime. The importance of low temperature studies is motivated by the application of CSAR 62 for deterministic nanophotonic device processing by means of in si...

Deterministically fabricated spectrally-tunable quantum dot based single-photon source

Schmidt, Marco ; Helversen, Martin V. ; Fischbach, Sarah ; Kaganskiy, Arsenty ; Schmidt, Ronny ; Schliwa, Andrei ; Heindel, Tobias ; Rodt, Sven ; Reitzenstein, Stephan (2020)

Spectrally-tunable quantum light sources are key elements for the realization of long-distance quantum communication. A deterministically fabricated single-photon source with a photon extraction efficiency of η =(20 ± 2) %, a maximum tuning range of ΔE = 2.5 meV and a minimum g(2)(τ = 0) = 0.03 ± 0.02 is presented. The device consists of a single pre-selected quantum dot (QD) monolithically int...

Non-Markovian features in semiconductor quantum optics: quantifying the role of phonons in experiment and theory

Carmele, Alexander ; Reitzenstein, Stephan (2019-04-23)

We discuss phonon-induced non-Markovian and Markovian features in QD-based quantum nanooptics. We cover lineshapes in linear absorption experiments, phonon-induced incoherence in the Heitler regime, and memory correlations in two-photon coherences. To qualitatively and quantitatively understand the underlying physics, we present several theoretical models that capture the non-Markovian properti...

Quantum metrology of solid-state single-photon sources using photon-number-resolving detectors

Helversen, Martin von ; Böhm, Jonas ; Schmidt, Marco ; Gschrey, Manuel ; Schulze, Jan-Hindrik ; Strittmatter, André ; Rodt, Sven ; Beyer, Jörn ; Heindel, Tobias ; Reitzenstein, Stephan (2019-03-28)

Quantum-light sources based on semiconductor quantum dots (QDs) are promising candidates for many applications in quantum photonics and quantum communication. Important emission characteristics of such emitters, namely the single-photon purity and photon indistinguishability, are usually assessed via time-correlated measurements using standard 'click' detectors in Hanbury Brown and Twiss or Hon...

Mode-switching induced super-thermal bunching in quantum-dot microlasers

Redlich, Christoph ; Lingnau, Benjamin ; Holzinger, Steffen ; Schlottmann, Elisabeth ; Kreinberg, Sören ; Schneider, Christian ; Kamp, Martin ; Höfling, Sven ; Wolters, Janik ; Reitzenstein, Stephan ; Lüdge, Kathy (2016-06-09)

The super-thermal photon bunching in quantum-dot (QD) micropillar lasers is investigated both experimentally and theoretically via simulations driven by dynamic considerations. Using stochastic multi-mode rate equations we obtain very good agreement between experiment and theory in terms of intensity profiles and intensity-correlation properties of the examined QD micro-laser's emission. Furthe...

Pump-Power-Driven Mode Switching in a Microcavity Device and Its Relation to Bose-Einstein Condensation

Leymann, H. A. M. ; Vorberg, D. ; Lettau, T. ; Hopfmann, Caspar ; Schneider, C. ; Kamp, M. ; Höfling, S. ; Ketzmerick, R. ; Wiersig, J. ; Reitzenstein, Stephan ; Eckardt, A. (2017-06-22)

We investigate the switching of the coherent emission mode of a bimodal microcavity device, occurring when the pump power is varied. We compare experimental data to theoretical results and identify the underlying mechanism based on the competition between the effective gain, on the one hand, and the intermode kinetics, on the other. When the pumping is ramped up, above a threshold, the mode wit...

Plug&Play Fiber‐Coupled 73 kHz Single‐Photon Source Operating in the Telecom O‐Band

Musiał, Anna ; Żołnacz, Kinga ; Srocka, Nicole ; Kravets, Oleh ; Große, Jan ; Olszewski, Jacek ; Poturaj, Krzysztof ; Wójcik, Grzegorz ; Mergo, Paweł ; Dybka, Kamil ; Dyrkacz, Mariusz ; Dłubek, Michał ; Lauritsen, Kristian ; Bülter, Andreas ; Schneider, Philipp‐Immanuel ; Zschiedrich, Lin ; Burger, Sven ; Rodt, Sven ; Urbańczyk, Wacław ; Sęk, Grzegorz ; Reitzenstein, Stephan (2020-05-11)

A user‐friendly, fiber‐coupled, single‐photon source operating at telecom wavelengths is a key component of photonic quantum networks providing long‐haul, ultra‐secure data exchange. To take full advantage of quantum‐mechanical data protection and to maximize the transmission rate and distance, a true quantum source providing single photons on demand is highly desirable. This great challenge is...

Quantum dot single-photon emission coupled into single-mode fibers with 3D printed micro-objectives

Bremer, Lucas ; Weber, Ksenia ; Fischbach, Sarah ; Thiele, Simon ; Schmidt, Marco ; Kaganskiy, Arsenty ; Rodt, Sven ; Herkommer, Alois ; Sartison, Marc ; Portalupi, Simone Luca ; Michler, Peter ; Giessen, Harald ; Reitzenstein, Stephan (2020-10-01)

User-friendly single-photon sources with high photon-extraction efficiency are crucial building blocks for photonic quantum applications. For many of these applications, such as long-distance quantum key distribution, the use of single-mode optical fibers is mandatory, which leads to stringent requirements regarding the device design and fabrication. We report on the on-chip integration of a qu...

Development of site-controlled quantum dot arrays acting as scalable sources of indistinguishable photons

Große, Jan ; Helversen, Martin von ; Koulas-Simos, Aris ; Hermann, Martin ; Reitzenstein, Stephan (2020-09-17)

We report on the realization of an array of 28 × 28 mesas with site-controlled InGaAs quantum dots acting as single-photon sources for potential applications in photonic quantum technology. The site-selective growth of quantum dots is achieved by using the buried stressor approach where an oxide aperture serves as the nucleation site in the center of each mesa. Spectroscopic maps demonstrate th...

Radiometric characterization of a triggered narrow-bandwidth single-photon source and its use for the calibration of silicon single-photon avalanche detectors

Georgieva, Hristina ; López, Marco ; Hofer, Helmuth ; Christinck, Justus ; Rodiek, Beatrice ; Schnauber, Peter ; Kaganskiy, Arsenty ; Heindel, Tobias ; Rodt, Sven ; Reitzenstein, Stephan ; Kück, Stefan (2020-09-07)

The traceability of measurements of the parameters characterizing single-photon sources, such as photon flux and optical power, paves the way towards their reliable comparison and quantitative evaluation. In this paper, we present an absolute measurement of the optical power of a single-photon source based on an InGaAs quantum dot under pulsed excitation with a calibrated single-photon avalanch...

Deterministisch integrierte Quantenpunkt-Wellenleiter-Halbleiterbauelemente

Schnauber, Peter Felix (2020)

Optische Quantenschaltkreise können realisiert werden, indem hunderte Einzelphotonenquellen, Interferometer und Detektoren durch Wellenleiter verbunden werden. Die Herstellung integrierter Wellenleiter-Einzelphotonenquellen ist Gegenstand weltweiter Forschung. In dieser Arbeit wird demonstriert, dass mit der „in-situ Elektronenstrahllithografie“ (in-situ EBL) Quantenpunkte (QPe) als Quellen ein...

Single-photon emission at a rate of 143 MHz from a deterministic quantum-dot microlens triggered by a mode-locked vertical-external-cavity surface-emitting laser

Schlehahn, Alexander ; Gaafar, M. ; Vaupel, M. ; Gschrey, Manuel ; Schnauber, Peter ; Schulze, Jan-Hindrik ; Rodt, Sven ; Strittmatter, André ; Stolz, W. ; Rahimi-Iman, A. ; Heindel, Tobias ; Koch, M. ; Reitzenstein, Stephan (2015-07-27)

We report on the realization of a quantum dot (QD) based single-photon source with a record-high single-photon emission rate. The quantum light source consists of an InGaAs QD which is deterministically integrated within a monolithic microlens with a distributed Bragg reflector as back-side mirror, which is triggered using the frequency-doubled emission of a mode-locked vertical-external-cavity...