700 research outputs found
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
This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Appl. Phys. Lett. 107, 041105 (2015) and may be found at https://doi.org/10.1063/1.4927429.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 surface-emitting laser (ML-VECSEL). The utilized compact and stable laser system allows us to excite the single-QD microlens at a wavelength of 508 nm with a pulse repetition rate close to 500 MHz at a pulse width of 4.2 ps. Probing the photon statistics of the emission from a single QD state at saturation, we demonstrate single-photon emission of the QD-microlens chip with g(2)(0) < 0.03 at a record-high single-photon flux of (143 ± 16) MHz collected by the first lens of the detection system. Our approach is fully compatible with resonant excitation schemes using wavelength tunable ML-VECSELs, which will optimize the quantum optical properties of the single-photon emission in terms of photon indistinguishability.BMBF, 03V0630, Entwicklung einer Halbleiterbasierten Einzelphotonenquelle für die Quanteninformationstechnologie (QSOURCE)DFG, 43659573, SFB 787: Halbleiter - Nanophotonik: Materialien, Modelle, BauelementeDFG, 192635911, GRK 1782: Funktionalisierung von HalbleiternDFG, 223848855, SFB 1083: Struktur und Dynamik innerer Grenzfläche
On-chip light detection using monolithically integrated quantum dot micropillars
This work was supported by the German Research Foundation (DFG) under Grants RE2974/9-1 and SCHN1376/1-1. The research leading to these results has received funding from the European Research Council under the European Union's Seventh Framework ERC Grant Agreement No. 615613.We demonstrate the on-chip detection of light using photosensitive detectors based on quantum dot (QD) micropillar cavities. These microscale detectors are applied exemplarily to probe the emission of a monolithically integrated, electrically pumped whispering gallery mode microlaser. Light is detected via the photocurrent induced in the electrically contacted micropillar detectors under reverse-bias. In order to demonstrate the high potential and applicability of the microdetector presented, we determine the threshold current of an integrated microlaser to be (54 ± 4) μA, in very good agreement with the value of (53 ± 4) μA inferred from optical data. Within this work we realize the monolithic integration of a laser and a detector in a single device operating in the regime of cavity-quantum electrodynamics. Our results thus advance the research on microscale sensor technology towards the few-photon quantum limit and pave the way for on-chip opto-electronic feedback experiments.PostprintPeer reviewe
Telehealth Student Experiences and Learning: A Scoping Review
Telehealth as a service delivery model is increasing in popularity. Knowledge and use of telehealth technology will be a new mandatory learning outcome in occupational therapy curriculums with the implementation of the 2018 Accreditation Council for Occupational Therapy Education standards. However, it is not known how healthcare programs are currently incorporating telehealth into education or which methods of telehealth education are most effective. This study addressed this gap in the literature using Arksey and O’Malley’s five-step methodological process to conduct a scoping review to examine the student experience of delivering healthcare services via telehealth and related learning outcomes. The scoping review encompassed eight databases with inclusion criteria of articles that discussed student learning outcomes, telehealth or telemedicine, and the student experience of delivering telehealth services. The research team screened 955 articles, reviewed 24 full-text articles, and came to a consensus on six articles to include in the review. Findings suggested a high level of student satisfaction related to the experience of delivering healthcare services using telehealth. Results indicated that students have a variety of related learning outcomes including increased knowledge of their professional practice, increased cultural competence, increased knowledge of how to work on interprofessional teams, and increased knowledge and skill in the use of technology. The review revealed a need for objective measures to examine specific student learning outcomes related to utilizing telehealth as a service delivery method. Additionally, the review indicated a need for future research to identify best educational practices for teaching students about telehealth
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