| 1. |
- Belonovskii, A. V., et al.
(författare)
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Strong Coupling of Excitons in Hexagonal GaN Microcavities
- 2020
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Ingår i: Semiconductors (Woodbury, N.Y.). - : PLEIADES PUBLISHING INC. - 1063-7826 .- 1090-6479. ; 54:1, s. 127-130
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Tidskriftsartikel (refereegranskat)abstract
- The GaN planar hexagonal microcavities are grown by the selective vapor-phase epitaxy technique. The spectra are measured by the low-temperature cathodoluminescence method using a scanning electron microscope. The obtained spectra show a huge Rabi splitting (similar to 100 meV). Numerical simulation of the spatial distribution of the intensities of modes in a hexagonal cavity is carried out. Certain modes can have a high spatial localization leading to strong coupling with the exciton and huge Rabi splitting. The fraction of excitons in polariton modes, which correlates with the intensity of exciton radiation associated with these modes, is theoretically calculated for hexagonal-shaped microcavities. Thus, the form of the dependence of the radiation probability on the eigenfrequencies of the structure is obtained.
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| 2. |
- Gubaydullin, A. R., et al.
(författare)
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Control of spontaneous emission rate in Tamm plasmon structures
- 2018
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Ingår i: 2018 INTERNATIONAL CONFERENCE LASER OPTICS (ICLO 2018). - : IEEE. - 9781538636121 ; , s. 131-131
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Konferensbidrag (refereegranskat)abstract
- We have studied experimentally and theoretically spontaneous emission rate modification in Tamm plasmon structures with semiconductor( InAs/GaAs quantum dots) and organic (CBP) emitters. Time-resolved spectroscopy demonstrates that spontaneous emission rate is increased by one order in magnitude. Experimentally measured spontaneous emission pattern coincides with calculated dependence of modal Purcel factor on frequency and angle of emission.
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| 3. |
- Gubaydullin, A. R., et al.
(författare)
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Enhancement of spontaneous emission in Tamm plasmon structures
- 2017
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Ingår i: Scientific Reports. - : NATURE PUBLISHING GROUP. - 2045-2322. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- It was theoretically and experimentally demonstrated that in metal/semiconductor Tamm plasmon structures the probability of spontaneous emission can be increased despite losses in metal, and theoretical analysis of experimental results suggested that the enhancement could be as high as one order of magnitude. Tamm plasmon structure with quantum dots has been fabricated and the emission pattern has been measured. Electromagnetic modes of the structure have been analyzed and modification of spontaneous emission rates has been calculated showing a good agreement with experimentally observed emission pattern.
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| 4. |
- Pozina, Galia, et al.
(författare)
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Experimental Study of Spontaneous Emission in the Bragg Multiple Quantum Wells Structure of InAs Monolayers Embedded in a GaAs Matrix
- 2018
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Ingår i: Semiconductors (Woodbury, N.Y.). - : PLEIADES PUBLISHING INC. - 1063-7826 .- 1090-6479. ; 52:14, s. 1822-1826
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Tidskriftsartikel (refereegranskat)abstract
- Time-resolved photoluminescence of a Bragg structure of InAs-monolayer quantum wells in GaAs matrix was experimentally studied with. Comparison of luminescence patterns from the side and from the surface of a sample showed that Bragg-type ordering of quantum wells leads to a substantial alteration of the photoluminescence spectra including appearance of additional radiative modes. The sample side spectrum contains a single line corresponding to a ground state of an exciton. The surface spectrum at high excitation levels a new radiation line appears whose frequency and propagation angle correspond to the Bragg condition for quantum wells. A numerical calculation of the modal Purcell factor explains why the radiative emission amplification occurs only at a set of specific angles and frequencies, as opposed to the whole range that satisfies the Bragg condition.
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| 5. |
- Pozina, Galia, et al.
(författare)
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Super-radiant mode in InAs-monolayer-based Bragg structures
- 2015
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Ingår i: Scientific Reports. - : NATURE PUBLISHING GROUP. - 2045-2322. ; 5:14911
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Tidskriftsartikel (refereegranskat)abstract
- We report direct experimental evidence of the collective super-radiant mode in Bragg structure containing 60 InAs monolayer-based quantum wells (QWs) periodically arranged in GaAs matrix. Time-resolved photoluminescence measurements reveal an appearance of the additional super-radiant mode, originated from coherent collective interaction of QWs. This mode demonstrates a super-linear dependence of the intensity and radiative decay rate on the excitation power. The superradiant mode is not manifested in the case if only a small number of QWs is excited.
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| 6. |
- Gubaydullin, A. R., et al.
(författare)
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Purcell Effect in Tamm Plasmon Structures with QD Emitter
- 2018
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Ingår i: Semiconductors (Woodbury, N.Y.). - : MAIK NAUKA/INTERPERIODICA/SPRINGER. - 1063-7826 .- 1090-6479. ; 52:4, s. 452-457
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Tidskriftsartikel (refereegranskat)abstract
- We study Tamm plasmon structure based on GaAs/Al0.95GaAs distributed Bragg reflector covered by thin silver layer, with active area formed by InAs quantum dots. We have measured the spectral and angular characteristics of photoluminescence and performed theoretical calculation of the spontaneous emission rate (modal Purcell factor) in the structure by using S-quantization formalism. We show that for Tamm plasmon mode the spontaneous emission can be enhanced by more than an order of magnitude, despite absorption in metallic layer.
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| 7. |
- Morozov, K. M., et al.
(författare)
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Different regimes of the Purcell effect in disordered photonic crystals
- 2018
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Ingår i: Journal of Physics. - : IOP PUBLISHING LTD. - 0953-8984 .- 1361-648X. ; 30:43
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate that disorder in photonic crystals could lead to pronounced modification of spontaneous emission rate in the frequency region corresponding to the photonic band gap (PBG). Depending on the amount of disorder, two different regimes of the Purcell effect occurs. We provide statistical analysis of Purcell coefficient on the frequency of the emitter and its position within the sample. For the moderate disorder, an enhancement of spontaneous emission occurs at the edge of PBG due to the modification of properties of the edge state. This effect is responsible for recently observed mirrorless lasing in photonic crystals at the edge of PBG. When the level of disorder increases, the spontaneous emission rate enhances within the PBG due to the appearance of the high quality factor states. This effect is likely responsible for a superlinear dependence of emissions on pumping observed in synthetic opals.
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| 8. |
- Morozov, K. M., et al.
(författare)
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Purcell effect in a disordered photonic crystals
- 2018
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Ingår i: 2018 INTERNATIONAL CONFERENCE LASER OPTICS (ICLO 2018). - : IEEE. - 9781538636121 ; , s. 310-310
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Konferensbidrag (refereegranskat)abstract
- We demonstrate that disorder in photonic crystals could lead to a modification of spontaneous emission rate in the frequency region corresponding to a photonic band gap (PBG). Depending on the amount of disorder two different regimes of Purcell effect occurs occurs. For weak disorder Purcell enhancement of spontaneous emission occurs at PBG edges, for strong disorder at PBG centre.
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| 9. |
- Morozov, K. M., et al.
(författare)
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Purcell effect in a disordered photonic crystals
- 2018
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Ingår i: 2018 DAYS ON DIFFRACTION (DD). - : IEEE. - 9781728103136 ; , s. 220-222
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Konferensbidrag (refereegranskat)abstract
- We consider the one-dimensional problem of imperfections influence on the Purcell effect in photonic crystal system. We demonstrate that the presence of disorder in a one-dimensional photonic crystal can lead to a modification of the spontaneous emission rate in the photonic band gap (PBG) frequency region. We show that the amount of disorder regulates two different scenarios of the Purcell effect modification. In the case of weak disorder, the Purcell enhancement of the spontaneous emission occurs at PBG edges, and, in the case of strong disorder, it occurs at PBG centre.
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| 10. |
- Pozina, Galia, et al.
(författare)
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Experimental Study of Spontaneous Emission in Bragg Multiple- Quantum-Well Structures with InAs Single-Layer Quantum Wells
- 2018
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Ingår i: Semiconductors (Woodbury, N.Y.). - : PLEIADES PUBLISHING INC. - 1063-7826 .- 1090-6479. ; 52:7, s. 877-880
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Tidskriftsartikel (refereegranskat)abstract
- The time-resolved photoluminescence of a Bragg structure formed by InAs single-layer quantum wells in a GaAs matrix is investigated experimentally. The comparison of photoluminescence spectra recorded from the edge and the surface of the sample indicates that Bragg ordering of the quantum wells leads to substantial modification of the spectra, in particular, to the appearance of additional modes. The spectrum recorded at the edge of the sample features a single line corresponding to the exciton ground state. In the spectrum recorded at the surface, an additional line whose frequency and propagation angle correspond to the Bragg condition for quantum wells, appears at high excitation levels. The calculation of the modal Purcell factor explains the fact that spontaneous emission is enhanced only for specific propagation angles and frequencies, rather than for all angles and frequencies satisfying the Bragg condition.
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