Resonant Optical Pumping, Read-out and Dynamics of a Mn Spin in a Quantum Dot

2011 ◽  
Author(s):  
C. Le Gall ◽  
R. Kolodka ◽  
H. Boukari ◽  
H. Mariette ◽  
L. Besombes ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Optical Pumping

Optical Nmr From Single Quantum Dots

1996 ◽  
Vol 442 ◽  
Author(s):  
S. W. Brown ◽  
T. A. Kennedy ◽  
D. Gammon
Keyword(s):  
Quantum Dots ◽  
Quantum Dot ◽  
Quantum Wells ◽  
Optical Pumping ◽  
Nuclear Orientation ◽  
Energy Levels ◽  
Zeeman Splitting ◽  
Single Quantum ◽  
Interface Fluctuations ◽  
20 Nm

AbstractWe have observed nuclear magnetic resonance (NMR) signatures from constituent Ga and As nuclei in single GaAs quantum dots formed by interface fluctuations in GaAs/AlGaAs quantum wells. Orientation of the nuclear spin system by optical pumping causes an Overhauser shift in the excitonic energy levels proportional to the degree of nuclear orientation. NMR was detected by monitoring changes in the combined Overhauser plus Zeeman splitting of an exciton localized in a single quantum dot as the RF frequency was swept through a nuclear resonance. The NMR signals originate from ∼105 nuclei in the quantum dot — (20 nm)3 volume - representing an increase in sensitivity of five orders of magnitude over previous optical NMR measurements and thirteen orders of magnitude over conventional NMR. The data were fit to Lorentzian lineshapes, giving 75As linewidths on the order of 20 kHz.

scholarly journals Субмонослойные квантовые точки InGaAs/GaAs, выращенные методом МОС-гидридной эпитаксии

2019 ◽  
Vol 53 (8) ◽  
pp. 1159
Author(s):  
В.Я. Алешкин ◽  
Н.В. Байдусь ◽  
А.А. Дубинов ◽  
К.Е. Кудрявцев ◽  
С.М. Некоркин ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Quantum Dot ◽  
Room Temperature ◽  
Optical Pumping ◽  
Liquid Nitrogen Temperature ◽  
Stimulated Emission ◽  
Threshold Power ◽  
Gaas Substrates ◽  
Dot Density ◽  
Hydride Epitaxy

AbstractThe mode of the growth of InGaAs quantum dots by MOS-hydride epitaxy on GaAs substrates without a deviation and with a deviation of 2° is selected for laser structures emitting at wavelengths above 1.2 μm at room temperature. As a result, a quantum-dot density of 4 × 10^10 cm^–2 is achieved. Stimulated emission is observed in laser structures with seven layers of quantum dots at a wavelength of 1.06 μm at liquid-nitrogen temperature. The threshold power density of optical pumping is about 5 kW/cm^2.

scholarly journals Enhancement of Light Amplification of CsPbBr3 Perovskite Quantum Dot Films via Surface Encapsulation by PMMA Polymer

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2574
Author(s):  
Saif M. H. Qaid ◽  
Hamid M. Ghaithan ◽  
Khulod K. AlHarbi ◽  
Bandar Ali Al-Asbahi ◽  
Abdullah S. Aldwayyan
Keyword(s):  
Quantum Dot ◽  
Optical Pumping ◽  
Photonic Devices ◽  
Perovskite Layer ◽  
Glass Substrates ◽  
Perovskite Materials ◽  
Laser Pumping ◽  
Light Amplification ◽  
Wide Range ◽  
Upper Face

Photonic devices based on perovskite materials are considered promising alternatives for a wide range of these devices in the future because of their broad bandgaps and ability to contribute to light amplification. The current study investigates the possibility of improving the light amplification characteristics of CsPbBr3 perovskite quantum dot (PQD) films using the surface encapsulation technique. To further amplify emission within a perovskite layer, CsPbBr3 PQD films were sandwiched between two transparent layers of poly(methyl methacrylate) (PMMA) to create a highly flexible PMMA/PQD/PMMA waveguide film configuration. The prepared perovskite film, primed with a polymer layer coating, shows a marked improvement in both emission efficiency and amplified spontaneous emission (ASE)/laser threshold compared with bare perovskite films on glass substrates. Additionally, significantly improved photoluminescence (PL) and long decay lifetime were observed. Consequently, under pulse pumping in a picosecond duration, ASE with a reduction in ASE threshold of ~1.2 and 1.4 times the optical pumping threshold was observed for PQDs of films whose upper face was encapsulated and embedded within a cavity comprising two PMMA reflectors, respectively. Moreover, the exposure stability under laser pumping was greatly improved after adding the polymer coating to the top face of the perovskite film. Finally, this process improved the emission and PL in addition to enhancements in exposure stability. These results were ascribed in part to the passivation of defects in the perovskite top surface, accounting for the higher PL intensity, the slower PL relaxation, and for about 14 % of the ASE threshold decrease.

Highly Efficient Amplified Stimulated Emission from CdSe-CdS-ZnS Quantum Dot Doped Waveguides with Two-Photon Infrared Optical Pumping

2008 ◽  
Vol 20 (1) ◽  
pp. 69-73 ◽  
Author(s):  
J. J. Jasieniak ◽  
I. Fortunati ◽  
S. Gardin ◽  
R. Signorini ◽  
R. Bozio ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Optical Pumping ◽  
Stimulated Emission ◽  
Two Photon ◽  
Highly Efficient ◽  
Amplified Stimulated Emission

LIGHT EMISSION, ABSORPTION AND AMPLIFICATION IN InAs/GaAs QUANTUM DOTS AND GaAs/AlGaAs QUANTUM WELLS RESULTING FROM OPTICAL PUMPING

2007 ◽  
Vol 06 (03n04) ◽  
pp. 241-244 ◽  
Author(s):  
D. A. FIRSOV ◽  
L. E. VOROBJEV ◽  
M. A. BARZILOVICH ◽  
V. YU. PANEVIN ◽  
I. V. MIKHAYLOV ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Quantum Wells ◽  
Light Absorption ◽  
Optical Pumping ◽  
Light Emission ◽  
Optical Excitation ◽  
Ground Level ◽  
Infrared Light ◽  
Mid Infrared ◽  
Gaas Quantum Dot

Optical phenomena in quantum dot and quantum well nanostructures aimed at the development of mid-infrared lasers based on intraband electron transitions are investigated in the conditions of interband optical pumping. Evolution of photoluminescence spectra and interband light absorption with intensity of interband optical excitation is investigated in InAs / GaAs quantum dot structures. Optically induced intersubband mid-infrared light absorption is studied in undoped tunnel-coupled GaAs / AlGaAs quantum wells. The stabilization of the electron concentration at the ground level of tunnel-coupled quantum wells under increasing pumping level is established.

scholarly journals Bright Single-Photon Emitters with a CdSe Quantum Dot and Multimode Tapered Nanoantenna for the Visible Spectral Range

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 916
Author(s):  
Maxim Rakhlin ◽  
Sergey Sorokin ◽  
Dmitrii Kazanov ◽  
Irina Sedova ◽  
Tatiana Shubina ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Spectral Range ◽  
Focused Ion Beam ◽  
Optical Pumping ◽  
Single Photon ◽  
Ion Beam ◽  
Visible Spectral Range ◽  
Single Photons ◽  
Free Space Optical ◽  
Single Photon Emitters

We report on single photon emitters for the green-yellow spectral range, which comprise a CdSe/ZnSe quantum dot placed inside a semiconductor tapered nanocolumn acting as a multimode nanoantenna. Despite the presence of many optical modes inside, such a nanoantenna is able to collect the quantum dot radiation and ensure its effective output. We demonstrate periodic arrays of such emitters, which are fabricated by focused ion beam etching from a II-VI/III-V heterostructure grown using molecular beam epitaxy. With non-resonant optical pumping, the average count rate of emitted single photons exceeds 5 MHz with the second-order correlation function g(2)(0) = 0.25 at 220 K. Such single photon emitters are promising for secure free space optical communication lines.

scholarly journals Optical pumping of quantum dot micropillar lasers

2021 ◽  
Author(s):  
Louis Andréoli ◽  
Xavier Porte ◽  
Tobias Heuser ◽  
Jan Große ◽  
Baptiste Moeglen-Paget ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Optical Pumping
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