scholarly journals Temperature-dependent dark-field scattering of single plasmonic nanocavity

Nanophotonics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 3347-3356 ◽  
Author(s):  
Wei Jiang ◽  
Huatian Hu ◽  
Qian Deng ◽  
Shunping Zhang ◽  
Hongxing Xu
Keyword(s):  
Plasmon Resonance ◽  
Phonon Scattering ◽  
Dark Field ◽  
Basic Knowledge ◽  
Temperature Dependent ◽  
Au Film ◽  
Au Nanowire ◽  
Key Factor ◽  
Particle Level ◽  
Electromagnetic Calculations

AbstractPlasmonic materials have long been exploited for enhanced spectroscopy, integrated nanophotonic circuits, sensing, light harvesting, etc. Damping is the key factor that limits their performance and restricts the development of the field. Optical characterization of single nanoparticle at low temperature is ideal for investigating the damping of plasmons but is usually technically impractical due to the sample vibration from the cryostat and the surface adsorption during the cooling process. In this work, we use a vibration-free cryostat to investigate the temperature-dependent dark-field scattering spectroscopy of a single Au nanowire on top of a Au film. This allows us to extract the contribution of electron-phonon scattering to the damping of plasmons without performing statistics over different target nanoparticles. The results show that the full width at half-maximum of the plasmon resonance increases by an amount of 5.8%, over the temperature range of 5−150 K. Electromagnetic calculations reveal that the temperature-insensitive dissipation channels into photons or surface plasmon polaritons on the Au film contribute up to 64% of the total dissipations at the plasmon resonance. This explains why the reduction of plasmon linewidth seems small at the single-particle level. This study provides a more explicit measurement on the damping process of the single plasmonic nanostructure, which serves as basic knowledge in the applications of nanoplasmonic materials.

scholarly journals An Enhanced Plastic Optical Fiber-Based Surface Plasmon Resonance Sensor with a Double-Sided Polished Structure

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1516
Author(s):  
Lian Liu ◽  
Shijie Deng ◽  
Jie Zheng ◽  
Libo Yuan ◽  
Hongchang Deng ◽  
...  
Keyword(s):  
Surface Plasmon Resonance ◽  
Optical Fiber ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Low Cost ◽  
Fiber Axis ◽  
Plastic Optical Fiber ◽  
Au Film ◽  
Spr Sensor ◽  
Resonance Sensor

An enhanced plastic optical fiber (POF)-based surface plasmon resonance (SPR) sensor is proposed by employing a double-sided polished structure. The sensor is fabricated by polishing two sides of the POF symmetrically along with the fiber axis, and a layer of Au film is deposited on each side of the polished region. The SPR can be excited on both polished surfaces with Au film coating, and the number of light reflections will be increased by using this structure. The simulation and experimental results show that the proposed sensor has an enhanced SPR effect. The visibility and full width at half maximum (FWHM) of spectrum can be improved for the high measured refractive index (RI). A sensitivity of 4284.8 nm/RIU is obtained for the double-sided POF-based SPR sensor when the measured liquid RI is 1.42. The proposed SPR sensor is easy fabrication and low cost, which can provide a larger measurement range and action area to the measured samples, and it has potential application prospects in the oil industry and biochemical sensing fields.

The phonon scattering mechanism and its effect on temperature dependent thermal and thermoelectric properties of the silver nanowire

2022 ◽  
Author(s):  
Gui-Cang He ◽  
Lina Shi ◽  
Yilei Hua ◽  
Xiao-Li Zhu
Keyword(s):  
Thermoelectric Properties ◽  
Phonon Scattering ◽  
Silver Nanowire ◽  
Scattering Mechanism ◽  
Temperature Dependent ◽  
Scattering Mechanisms ◽  
Phonon Structure

In this work, the electron-phonon, the phonon-phonon, and phonon structure scattering mechanisms and the effect on the thermal and thermoelectric properties of the silver nanowire (AgNW) are investigated in temperature...

Climate Change Effects on Venomous Snakes

2019 ◽  
pp. 475-490
Author(s):  
Abdellah Bouazza ◽  
Moulay Abdelmonaim El Hidan ◽  
Abdelmohcine Aimrane ◽  
Kholoud Kahime ◽  
Aziza Lansari ◽  
...  
Keyword(s):  
Basic Knowledge ◽  
Human Populations ◽  
High Tendency ◽  
Snake Species ◽  
Clinical Scales ◽  
Climate Change Effects ◽  
Venomous Snakes ◽  
Key Factor ◽  
The Face ◽  
Snake Toxins

The purpose of this chapter is to examine the evidence of a relationship between climatic changes and snake species distribution in relation with the snakebites risk increment against human populations. The global climatic change is a key factor leading to snake species behavioral changes mainly because of the rise of temperature. The variety of venomous snakes and their related potency toward human being have been well documented. Thus, this may serve as a basic knowledge for any preventive act in the face of snake toxins and their caused physiopathological and clinical effects. In addition, several studies have shown that global warming have caused a change in snake habitat and distribution, thus leading to an increase of overlapped human and snake populations living territories which raise up the risk of envenomation. Globally, more than 20,000 deaths occur every year with a high tendency to increase. Thus, consideration of human risk of envenomation may be fundamental to the effective intervention in epidemiological and clinical scales.

THE EFFECTS OF TEMPERATURE ON DIFFERENT LASER TRANSITIONS OF NEODYMIUM ORTHOVANADATE CRYSTAL

2016 ◽  
Vol 78 (3) ◽  
Author(s):  
Ganesan Krishnan ◽  
Noriah Bidin
Keyword(s):  
Laser Diode ◽  
Ground State ◽  
Phonon Scattering ◽  
Laser Crystal ◽  
Laser System ◽  
Temperature Dependent ◽  
Laser Transition ◽  
Level Laser ◽  
Effects Of Temperature ◽  
Terminal Level

The temperature dependence of Nd:YVO4 laser crystal pumped by laser diode emitting at 808 nm is studied within the range of 5 oC to 60 oC. The spectroscopy properties of quasi three level at 914 nm (4F3/2 - 4I 9/2) and four level at 1064 nm (4F3/2 - 4I 11/2) are characterized. The lineshape function of the transition lines were broadened as the temperature increases. The phenomenon is attributed to change in linewidth, lineshift and intensity. The linewidths for both laser transition of 914 nm and 1064 nm increases with temperature with the rate of 0.105 cm-1/oC and 0.074 cm-1/oC respectively. The peak of 914nm and 1064 nm lineshapes shifted to a longer wavelength with the rate of 3.0 pm/oC and 4.2 pm/oC respectively which correspond to same amount of lineshift. The lineshape broadening with respect to the temperature is due to one-phonon emission and Raman phonon scattering processes.  The intensities of 914 nm and 1064 nm transition lines are found to be decreased at the rate of 0.15 %/oC and 0.45 %/oC respectively due to non-radiative effects. Quasi three level laser transition is more temperature dependent because it terminal level is close to the ground state which suffers from higher phonon-ion interaction rather than four level laser system.

Intestinal Mucosal and Serosal Microcirculation at the Planned Anastomosis during Abdominal Surgery

2019 ◽  
Vol 60 (5-6) ◽  
pp. 248-256 ◽  
Author(s):  
Arthur L.M. Tavy ◽  
Anton F.J. de Bruin ◽  
Anke B. Smits ◽  
E. Christiaan Boerma ◽  
Can Ince ◽  
...  
Keyword(s):  
Anastomotic Leakage ◽  
Dark Field ◽  
Vessel Density ◽  
Flow Index ◽  
Dark Field Imaging ◽  
Key Factor ◽  
Observational Cohort ◽  
Incident Dark Field Imaging ◽  
Field Imaging ◽  
Total Vessel Density

Introduction: Intestinal blood flow is often named as a key factor in the pathophysiology of anastomotic leakage. The distribution between mucosal and serosal microperfusion during surgery remains to be elucidated. Objective: The aim of this study was to assess if the mucosal microcirculation of the intestine is more vulnerable to a surgical hit than the serosal microcirculation during surgery. Methods: In an observational cohort study (n = 9 patients), the microcirculation of the bowel serosa and mucosa was visualized with incident dark-field imaging during surgery. At the planned anastomosis, the following microcirculatory parameters were determined: microvascular flow index (MFI), percentage of perfused vessels (PPV), perfused vessel density (PVD), and total vessel density (TVD). Data are presented as median (interquartile range [IQR]). Results: Perfusion parameters and vessel density were significantly higher for the mucosa than the serosal microcirculation at the planned site for anastomosis or stoma. Mucosal MFI was 3.00 (IQR 3.00–3.00) compared to a serosal MFI of 2.75 (IQR 2.21–2.94), p = 0.03. The PPV was 99% (IQR 98–100) versus 92% (IQR 66–94), p = 0.01. The TVD was 16.77 mm/mm2 (IQR 13.04–18.01) versus 10.42 mm/mm2 (IQR 9.36–11.81), p = 0.01, and the PVD was 15.44 mm/mm2 (IQR 13.04–17.78) versus 9.02 mm/mm2 (IQR 6.43–9.43), p = 0.01. Conclusions: The mucosal microcirculation was preserved, while lower perfusion of the serosa was found at the planned anastomosis or stoma during surgery. Further research is needed to link our observations to the clinically relevant endpoint of anastomotic leakage.

PHOTOLUMINESCENCE OF ULTRA SMALL InAs/GaAs QUANTUM DOTS

2005 ◽  
Vol 19 (18) ◽  
pp. 907-917 ◽  
Author(s):  
Y. G. LIN ◽  
C. H. WU ◽  
S. L. TYAN ◽  
S. D. LIN ◽  
C. P. LEE
Keyword(s):  
Quantum Dots ◽  
Phonon Scattering ◽  
Transition Energy ◽  
Tunneling Effect ◽  
Energy Separation ◽  
Hole State ◽  
Temperature Dependent ◽  
Pl Spectra ◽  
Shape Dependence ◽  
Electron And Hole States

The InAs/GaAs quantum dots (QDs) with a baselength of less than 10 nm are studied by the excitation-, temperature-dependent and magneto-photoluminescence (PL). The baselengths of the QDs, calculated by the PL ground state transition energy and estimated by magneto-PL spectra, are in agreement with the result of atomic force microscopy measurements. By means of the excitation-dependent PL, we demonstrate that only the ground electron and hole states exist when the baselength of the QDs is smaller than about 7.3 nm, whereas the larger dots with a baselength of about 8.7 nm will give rise to one excited hole state. The measured energy separation between the ground and the excited hole states is in good agreement with the theoretical calculation. The transition energy in temperature-dependent PL spectra shows a rapid redshift as the temperature is higher than the critical temperature. The redshift rate is about 2.8 and 2.5 times larger than the values calculated by Varshni's law for small and large dots respectively. The higher redshift rate can be explained by the stronger tunneling effect. In addition, the PL linewidths show a V-shape dependence with the temperature. This behavior could be well described as a tunneling and electron-phonon scattering effect.

Nucleation, growth, and aggregation of gold on polyimide surfaces

1999 ◽  
Vol 14 (9) ◽  
pp. 3673-3683 ◽  
Author(s):  
Y. Travaly ◽  
L. Zhang ◽  
Y. Zhao ◽  
R. Pfeffer ◽  
K. Uhrich ◽  
...  
Keyword(s):  
Room Temperature ◽  
Film Growth ◽  
Contact Angles ◽  
Thin Film Growth ◽  
Hole Filling ◽  
Temperature Dependent ◽  
Au Film ◽  
The Stability ◽  
Pi System ◽  
Thermal Stability Of

The growth of ultrathin gold films on polyimide (PI) surfaces and the stability of the films upon thermal annealing have been studied using a combination of various techniques. With scanning electron microscopy (SEM) we observe that, at room temperature, the Au film initially grows by nucleation of compact Au islands. With increasing metal coverage, the clusters partially agglomerate to produce a wormlike structure. Finally, percolation, hole-filling, and continuous thin-film growth are observed. To evaluate the thermal stability of the Au/PI system, annealing at various temperatures was performed on films that displayed the wormlike structure. SEM results indicate strong temperature-dependent changes in film morphology. Finally, from our SEM data we determine contact angles, allowing us to estimate interfacial and adhesion energies.

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