2018 Session – Quantum integrated photonics

Advances in Quantum Dot Lasers for Silicon Photonics

Yasuhiko Arakawa, Bongyong Jang, and Jinkwan Kwoen
Institute for Quantum Nano Infromation Electronics, The University of Tokyo 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505 Japan
Tel: +81354526245 Fax: +81354526246, e-mail: arakawa@iis.u-tokyo.c.

High temperature stability and high feedback-noise tolerance of the quantum dot lasers are advantageous features for silicon photonics. In this paper, we discuss recent progresses in quantum dot laser on silicon substrates. A silicon optical interposer incorporating InAs/GaAs quantum dot laser arrays via a flip-chip bonding method was demonstrated with the bandwidth-density of 15Tbps/cm2 at 125 °C. In addition, we report the first demonstration of a hybrid silicon quantum dot laser, evanescently coupled to a silicon waveguide. InAs/GaAs quantum laser structures are transferred, by means of direct wafer bonding, onto silicon waveguides defining cavities with adiabatic taper structures and distributed Bragg reflectors. Lasing operation has been realized above 100°C . Finally, we show an InAs/GaAs quantum dot laser directly grown on Si on-axis (100) substrate by the molecular beam epitaxy.

Keywords: quantum dot lasers, silicon photonics, integrated photonics, molecular beam epitaxy

We.2.A.1. 13-Invited Paper, Yasuhiko Arakawa (Univ. of Tokyo), “Quantum nanostructures and photonic devices”

Quantum Photonic Processor based on Silicon Nitride Waveguides

Caterina Taballione, Tom A. W. Wolterink, Andreas Eckstein, Jasleen Lugani, Robert Grootjans, Ilka Visscher, Jelmer J. Renema, Dimitri Geskus, Chris G. H. Roeloffzen, Ian A. Walmsley, Pepijn W. H. Pinkse and Klaus-Jochen Boller Laser Physics and Nonlinear Optics (LPNO), University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands. Tel: +31 53 489 5278, e-mail: c.taballione@utwente.nl
Ultrafast Quantum Optics and Optical Metrology, University of Oxford, Clarendon Laboratory, Parks Road, OXI 3PU Oxford, UK
Lionix International BV, PO Box 456, 7500 AL Enschede, The Netherlands
Complex Photonic Systems (COPS), University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands

Stoichiometric high-index-contrast silicon nitride waveguides can accomplish some of the important needs of photonic quantum information processing, such as high complexity and low loss. We demonstrate a versatile linear optical photonic processor for quantum information processing based on stoichiometric silicon nitride waveguides. The photonic processor is fully programmable and remotely controllable. The 8×8 unitary network is the largest fully programmable universal quantum photonic processor, based on silicon nitride waveguides realized so far. Demonstrating its versatile functionality we observe on-chip two-photon interference of high visibility, i.e., about 80%, with less than 10% variation in visibility between various nodes, i.e., beam splitters, of the photonic processor. Our findings show that stoichiometric silicon nitride is a promising platform for integrated, programmable quantum information processing.

Keywords: quantum information processing, linear optical processor, stoichiometric silicon nitride, two-photon interference.

We.2.A.2. 61-Highly Rated Paper, Quantum Photonic Processor based on Silicon Nitride Waveguides

Tilted-potential Photonic Crystal Cavities for Integrated Quantum Photonics

A. Delgoffe, A. Miranda, B. Rigal, A. Lyasota, A. Rudra, B. Dwir and E. Kapon Laboratory of Physics of Nanostructures, Institute of Physics
Ecole Polytechnique Fédérale de Lausanne (EPFL)
Route Cantonale – 1015, Lausanne – Switzerland
Tel: +41216933387, e-mail: antoine.delgoffe@epfl.ch

We demonstrate a novel, tailored-index photonic crystal cavity designed for optimal extraction and propagation of single photons in integrated quantum photonic chips. The structure consists in a line-defect photonic crystal waveguide with linear effective-index profile supporting Airy-function photonic modes. The observed modes are analyzed theoretically and experimentally using site-controlled quantum dot systems. Selective excitation of Airy-modes by properly positioned single quantum dots is demonstrated.

Keywords: photonic crystal cavities, tailored refractive index, optical disorder, single photon sources.

We.2.A.3. 47-Highly Rated Paper, Tilted-potential Photonic Crystal Cavities for Integrated Quantum Photonics

Photonic integration of quantum entropy sources

C. Abellan, W. Amaya, M. Rudé, D. Tulli, M. W. Mitchell and V. Pruneri
Quside Technologies S.L., C/Esteve Terradas 1, 08860 Castelldefels (Barcelona), Spain
ICFO-The Institute of Photonic Sciences, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
ICREA-Institució Catalana de Recerca i Estudis Avançats, Lluis Companys 23, 08010 Barcelona, Spain

In this talk, we will discuss recent progress on the miniaturisation of ultrafast quantum entropy sources based on the phase-diffusion mechanism present in pulsed semiconductor lasers. Recent results of the integration in silicon photonics and indium phosphide platforms will be presented, demonstrating that Gb/s quantum random number generation is feasible with current photonic integration technologies. This shows potential towards mass scale adoption of quantum and photonic components for cyber-security and super-computation.

Keywords: quantum technologies, integrated photonics, quantum entropy sources.

We.2.A.4. 27-Invited Paper, Carlos Abellan (Quside), “Photonic integration of quantum random number generators”

Integrated Quantum Photonics on Silicon Chips

Carsten Schuck
Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Straße 10 – 48149, Münster – Germany
Tel: +49 251 83 63948, e-mail: carsten.schuck@uni-muenster.de
Center for NanoTechnology (CeNTech), Heisenbergstraße 11 – 48149, Münster – Germany
Tel: +49 251 83 63948, e-mail: carsten.schuck@uni-muenster.de

Quantum technology that utilizes single-photons as information carriers promises more efficient computing and higher security in communication. The realization of such novel photonic quantum information processing systems requires the implementation of large numbers of single-photon sources, linear optical circuitry and efficient single-photon detectors. To overcome scalability limitations and interface with established telecommunication architecture, we develop a nanophotonic quantum technology platform on silicon chips, employing standard semiconductor thin-film processing. We generate non-classical photon-pairs at telecom wavelengths via spontaneous parametric down conversion in aluminum nitride micro-ring resonators. Antibunching of heralded single-photons with high modal purity highlights the suitability of this second-order nonlinear source for nanoscale quantum optics. Further, we developed a toolbox of nanophotonic components for integrated quantum circuits. Employing balanced directional couplers we demonstrate quantum interference with 97% visibility when measuring photon statistics with waveguide-coupled detectors directly on-chip. Embedding superconducting nanowire single-photon detectors with nanophotonic circuits enables us to count individual photons with high efficiency, negligible dark count rate and high timing accuracy, as desired for applications in quantum technology. Advanced nanofabrication routines allow for straightforward replication of such sources, circuits and detectors in large numbers on silicon chips, thus paving the way for scalable integrated quantum photonics.

Keywords: quantum interference, superconducting single-photon detectors, spontaneous parametric down conversion, nanophotonic waveguides.

We.2.A.5. 20-Invited Paper, Carsten Schuck (Univ. Munster), “Integrated quantum photonics”