In-Depth Experimental Analysis of Influence of Electroplated Gold Thickness on Thermal and Electro-Optical Properties of mid-IR AlInAs/InGaAs/InP Quantum Cascade Lasers

In this paper, we have examined the influence of electroplated gold thickness on the thermal and electro-optical properties of mid-IR AlInAs/InGaAs, InP QCLs. The experimental results show a significant reduction of the temperature of QCL active region (AR) with increasing gold layer thickness. For QCLs with 5.0 μm gold thickness, we observed a 50% reduction of the active region temperature. An improvement of key electro-optical parameters, that is, threshold current density and maximum emitted power for structures with thick gold, was observed. The results of micro-Raman characterization show that the electroplated gold layer introduces only moderate compressive strain in top InP cladding, which is well below the critical value for the creation of misfit dislocations.

Double-sided Polishing Photonic Crystal Fiber Biosensor Based on Surface Plasmon Resonance

In this paper, we propose a high-sensitivity double-sided polishing photonic crystal fiber biosensor based on surface plasmon resonance. The performance of the sensor was analyzed by finite element method, including the influence of different pore sizes and position, polishing depth, pore spacing, metal thickness, refractive index(RI), and manufacturing error (5%) on the sensing performance. We also analyze the performance of the modified sensor in early cancer detection applications. Our use of a double-sided polishing structure and coating with a gold layer not only increases the contact area between the analyte and gold layer but also provides a large enough space for the analysis channel, which is conducive to the actual manufacture and use. The sensor has a detection range of 1.35-1.39, the maximum wavelength sensitivity of 21500 nm/RIU, the average wavelength sensitivity is 9550 nm/RIU, the amplitude sensitivity of -1057.1756 RIU-1, the maximum resolution is 4.68×10-6, R2 of 0.98265, figure of merit is 250, and the maximum resolution of 4.68×10-6, which can be used in the cancer detection and other biological areas.

Surface Acoustic Wave Biosensor with Laser-Deposited Gold Layer Having Controlled Porosity

Laser-deposited gold immobilization layers having different porosities were incorporated into love wave surface acoustic wave sensors (LW-SAWs). Variation of pulsed laser deposition parameters allows good control of the gold film morphology. Biosensors with various gold film porosities were tested using the biotin–avidin reaction. Control of the Au layer morphology is important since the biotin and avidin layer morphologies closely follow that of the gold. The response of the sensors to biotin/avidin, which is a good indicator of biosensor performance, is improved when the gold layer has increased porosity. Given the sizes of the proteins, the laser-deposited porous gold interfaces have optimal pore dimensions to ensure protein stability.

Investigation On A Bio-Sensor: A Theoretical Study On Modified Photonic Crystal Fiber Using Plasmonic Nanomaterial

A modified (HC-800) Photonic Crystal Fiber (PCF) using Gold nanoparticle as an active plasmonic material was used as bio a sensor. The Finite Element Method is used to compute numerical interpretations of sensing performance employing various liquids such as (Liver Blood, Colon Blood, Human Blood Plasma, Water, and Pentanol). In the proposed biosensor the sample (analyte material) is placed into a core, cladding air holes, and outside of the HC fiber structure. The sensitivity was calculated before and after adding the gold layer. The maximum amplitude sensitivity was found to be 769.5749 RIU-1 for Human blood Plasma and the best electric field was found to be 400V/m. In the same liquid when used the deposited PCF with a gold layer the maximum amplitude sensitivity was found to be 975.5352 RIU-1 at a best electric field of 477 V/m. And when the proposed sensor is considered as a refractive index sensor, where is it used the analyte samples only (inside the core and air holes) of PCF. The maximum amplitude sensitivity was found to be 869.8453 RIU-1 at a best electric field of 434 V/m.

Three-band perfect absorber with high refractive index sensing based on active tunable Dirac semimetal

In this paper, we designed a three-band narrowband perfect absorber based on Bulk Dirac semimetallic (BDS) metamaterials. The absorber consists of a hollow Dirac semimetallic layer above, a gold layer...

Controlling Spontaneous Emission from Perovskite Nanocrystals with Metal–Emitter–Metal Nanostructures

We show the increase of the photoluminescence intensity ratio (PLR) and the emission rate enhancement of perovskite cesium lead bromide (CsPbBr3) and formamidinium lead bromide (FAPbBr3) nanocrystals (NCs) in the presence of single and double gold layer cavities, which we refer to as Metal-Emitter (ME) and Metal-Emitter-Metal (MEM) nanostructures. Up to 1.9-fold PLRs and up to 5.4-fold emission rate enhancements were obtained for FAPbBr3 NCs confined by double gold layers, which are attributed to plasmonic confinement from the gold layers. The experimentally obtained values are validated by analytical calculations and electromagnetic simulations. Such an effective method of manipulation of the spontaneous emission by simple plasmonic nanostructures can be utilized in sensing and detection applications.

ELECTRON-STIMULATED DESORPTION OF POTASSIUM ATOMS ADSORBED ON THE SURFACE OF GOLD

Создан ультратонкий слой интерметаллида KAu при комнатной температуре при напылении атомов калия на слой адсорбированного золота на поверхности вольфрама. Исследованы процессы электронно-стимулированной десорбции атомов K с поверхности KAu. Найдены квазирезонансные пики в зависимости выхода ЭСД от энергии возбуждения при 64 и 82 эВ, которые соответствуют возбуждению остовных уровней Au 5р и Au 5р. Полученные результаты свидетельствуют о формировании KAu различной стехиометрии: от KAu до KAu. Показано, что интерметаллид KAu, полученный при комнатной температуре, как полученный ранее KAu при 1000K, является полупроводником. Предложена модель электронно-стимулированной десорбции атомов K в системе K/KAu/Au/W. An ultrathin intermetallic layer KAuwas created at room temperature by depositing potassium atoms on adsorbed gold layer on the tungsten surface. The processes of electron-stimulated desorption of K atoms from the KAu surface are investigated. Quasi-resonance peaks are found in the dependence of the ESD yield on the excitation energy at 64 and 82 eV, which correspond to the excitation of the core levels Au 5p and Au 5p. The obtained results indicate the formation KAu of different stoichiometry: from KAu to KAu . It is shown that the intermetallic compound KAu created at room temperature is a semiconductor, as it was previously obtained at 1000 K. A model of electron-stimulated desorption of K atoms in the K / KAu / Au / W system is proposed.

Controlling Spontaneous Emission from Perovskite Nanocrystals with Metal-Emitter-Metal Nanostructures

We show the enhancement in the intensity and emission rate of perovskite cesium lead bromide (CsPbBr3) and formamidinium lead bromide (FAPbBr3) nanocrystals in the presence of single and double gold layer cavities, which we refer to as Metal-Emitter (ME) and Metal-Emitter-Metal (MEM) nanostructures. Up to 1.9-fold photoluminescence intensity and up to 5.4-fold emission rate enhancements were obtained for FAPbBr3 nanocrystals confined by double gold layers, which are attributed to plasmonic confinement from the gold layers. The experimentally obtained values are validated by analytical calculations and electromagnetic simulations. Such an effective method of manipulation of the spontaneous emission rate by simple plasmonic nanostructures can be utilized in sensing and detection applications.