scholarly journals Polishing of precision parts of optical-electronic and laser equipment

2021 ◽  
Author(s):  
Oksana Yurchyshyn ◽  
Yurii Filatov ◽  
V. Sidorko ◽  
Vasiliy Kovalov
Keyword(s):  
Energy Transfer ◽  
Dipole Interaction ◽  
Wear Intensity ◽  
Energy Transfer Mechanism ◽  
Optical Surfaces ◽  
Dispersed System ◽  
Quantum Mechanical Description ◽  
Donor Acceptor ◽  
Mechanism Of Interaction ◽  
Dispersed Material

The mechanism of interaction of the optical surface with the polishing dispersed system during polishing is investigated. It is established that the energy transfer between them is a consequence of the dipole-dipole interaction in the donor-acceptor system and occurs by the Ferster mechanism. It was found that the decrease in the spectral separation between the treated material and the particles of polishing powder causes an increase in the size of sludge particles and wear particles, which leads to an increase in the roughness parameters Ra, Rq, Rmax of optical surfaces during polishing by polishing dispersed sys-tems. It is shown that the polishing productivity of optical surfaces and the wear intensity of polishing powder particles decrease with increasing corresponding transfer energies, which confirms the main pro-visions of the cluster theory of polishing of nonmetallic materials and the validity of quantum mechanical description of resonant energy transfer mechanism between dispersed material and dispersed system.

Sensitizing effect of Yb3+ on near-infrared fluorescence emission of Cr4+-doped calcium aluminate glasses

2000 ◽  
Vol 15 (2) ◽  
pp. 278-281 ◽  
Author(s):  
Yong Gyu Choi ◽  
Kyong Hon Kim ◽  
Yong Seop Han ◽  
Jong Heo
Keyword(s):  
Energy Transfer ◽  
Calcium Aluminate ◽  
Near Infrared ◽  
Fluorescence Emission ◽  
Dipole Interaction ◽  
Energy Transfer Mechanism ◽  
Efficient Energy Transfer ◽  
Efficient Energy ◽  
Sensitizing Effect ◽  
Decay Behavior

We have demonstrated that an efficient energy transfer takes place from Yb3+ to Cr4+ in calcium aluminate glasses. Yb3+ improves excitation efficiency at around 980 nm, enhancing emission intensity of Cr4+ fluorescence at 1.2–1.6 μm. Nonradiative energy transfer via electric dipole–dipole interaction between ytterbium and chromium ions was found to be dominant over radiative Yb3+ → Cr4+ energy transfer. A diffusionlimited energy transfer mechanism well explains the decay behavior of Yb3+/Cr4+- codoped glasses. This codoping scheme may be applicable to other Cr4+-containing crystals and glasses.

scholarly journals Ферстеровский резонансный перенос энергии с участием светлых и темных экситонов в массивах эпитаксиальных квантовых точек CdSe/ZnSe

2018 ◽  
Vol 60 (8) ◽  
pp. 1575
Author(s):  
Т.Н. Михайлов ◽  
Е.А. Европейцев ◽  
К.Г. Беляев ◽  
A.A. Торопов ◽  
A.В. Родина ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Excited States ◽  
Energy Transfer Process ◽  
Dipole Interaction ◽  
Energy Transfer Mechanism ◽  
Time Resolved ◽  
Decay Times ◽  
Förster Energy Transfer ◽  
Excitonic States ◽  
Time Resolved Photoluminescence

AbstractUsing time-resolved photoluminescence (PL) spectroscopy, we establish the presence of the Förster energy transfer mechanism between two arrays of epitaxial CdSe/ZnSe quantum dots (QDs) of different sizes. The mechanism operates through dipole–dipole interaction between ground excitonic states of the smaller QDs and excited states of the larger QDs. The dependence of energy transfer efficiency on the width of barrier separating the QD insets is shown to be in line with the Förster mechanism. The temperature dependence of the PL decay times and PL intensity suggests the involvement of dark excitons in the energy transfer process.

Quantum Dot Bioconjugates as Energy Donors in Fluorescence Resonance Energy Transfer Assays

2003 ◽  
Vol 773 ◽  
Author(s):  
Aaron R. Clapp ◽  
Igor L. Medintz ◽  
J. Matthew Mauro ◽  
Hedi Mattoussi
Keyword(s):  
Energy Transfer ◽  
Quantum Dot ◽  
Organic Dyes ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Genetically Engineered ◽  
Molar Ratio ◽  
Binding Assays ◽  
Specific Sequence ◽  
Donor Acceptor

AbstractLuminescent CdSe-ZnS core-shell quantum dot (QD) bioconjugates were used as energy donors in fluorescent resonance energy transfer (FRET) binding assays. The QDs were coated with saturating amounts of genetically engineered maltose binding protein (MBP) using a noncovalent immobilization process, and Cy3 organic dyes covalently attached at a specific sequence to MBP were used as energy acceptor molecules. Energy transfer efficiency was measured as a function of the MBP-Cy3/QD molar ratio for two different donor fluorescence emissions (different QD core sizes). Apparent donor-acceptor distances were determined from these FRET studies, and the measured distances are consistent with QD-protein conjugate dimensions previously determined from structural studies.

Energy transfer mechanism of supersonic jet noise through rectangular nozzles

2017 ◽  
Vol 65 (2) ◽  
pp. 110-120 ◽  
Author(s):  
Zhe Chen ◽  
Jiu-Hui Wu ◽  
A-Dan Ren ◽  
Xin Chen ◽  
Zhen Huang
Keyword(s):  
Energy Transfer ◽  
Supersonic Jet ◽  
Jet Noise ◽  
Transfer Mechanism ◽  
Energy Transfer Mechanism ◽  
Supersonic Jet Noise

Luminescence Properties and energy transfer mechanism of Eu3+ and Tm3+ Co-doped AlN Thin Films

2021 ◽  
pp. 118082
Author(s):  
Hai Ma ◽  
Xiaodan Wang ◽  
Feifei Chen ◽  
Jiafan Chen ◽  
Xionghui Zeng ◽  
...  
Keyword(s):  
Thin Films ◽  
Energy Transfer ◽  
Transfer Mechanism ◽  
Luminescence Properties ◽  
Energy Transfer Mechanism ◽  
Co Doped

scholarly journals Ultrafast Electron/Energy Transfer and Intersystem Crossing Mechanisms in BODIPY-Porphyrin Compounds

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 312
Author(s):  
Yusuf Tutel ◽  
Gökhan Sevinç ◽  
Betül Küçüköz ◽  
Elif Akhuseyin Yildiz ◽  
Ahmet Karatay ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Fluorescence Spectra ◽  
Visible Region ◽  
Energy Transfer Mechanism ◽  
Free Base ◽  
Pump Probe ◽  
Harvesting Efficiency ◽  
Probe Spectroscopy ◽  
Absorption Features ◽  
Transfer Mechanisms

Meso-substituted borondipyrromethene (BODIPY)-porphyrin compounds that include free base porphyrin with two different numbers of BODIPY groups (BDP-TTP and 3BDP-TTP) were designed and synthesized to analyze intramolecular energy transfer mechanisms of meso-substituted BODIPY-porphyrin dyads and the effect of the different numbers of BODIPY groups connected to free-base porphyrin on the energy transfer mechanism. Absorption spectra of BODIPY-porphyrin conjugates showed wide absorption features in the visible region, and that is highly valuable to increase light-harvesting efficiency. Fluorescence spectra of the studied compounds proved that BODIPY emission intensity decreased upon the photoexcitation of the BODIPY core, due to the energy transfer from BODIPY unit to porphyrin. In addition, ultrafast pump-probe spectroscopy measurements indicated that the energy transfer of the 3BDP-TTP compound (about 3 ps) is faster than the BDP-TTP compound (about 22 ps). Since the BODIPY core directly binds to the porphyrin unit, rapid energy transfer was seen for both compounds. Thus, the energy transfer rate increased with an increasing number of BODIPY moiety connected to free-base porphyrin.

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