In this work, we fabricated an efficient macroporous silicon/gold nanoparticles (macro psi/AuNPs) hybrid structure and how well controlling of plasmonic features on macro psi/AuNPs employs them for highly sensitive detection of the very low concentration of cyanine (Cy) dyes molecules. Macro-PSi was synthesized on n-type Si wafer with 3-10 Ω. cm resistivity and 100 orientation using Photo Electro Chemical Etching (PECE) process with630 nm illumination wavelength and 30 mW/cm 2 illumination intensity. The macroPSi /AuNPs hybrid structure substrates were prepared by simple and quick dipping process of macroPSi in tetrachloroauric gold solution HAuCl 4 with different concentrations of (10
In this work we submit a simulation design to sense the water quality using hollow core photonic crystal fiber. The work of this types of optical fibers depending on the variety of structural design and geometrical parameters. The numerical results are studied by using the Finite Element Method (FEM) through COMSOL MULTIPHYSICS simulation software. Different concentrations from (0%) to (100%) of D2O and H2O2 solution in water as sensed liquid had been chosen. The studied HC-PCF investigated for analyzing the relative sensitivity, effective area and confinement loss at wavelength range from (1) µm to (2) µm.
Surface Plasmon Resonance (SPR) is the charge density excitation oscillation (surface Plasmon’s, (SP)) caused by the polarized light along with the metal-dielectric interface by agreeing to phase-matching condition between polarized light and SPR. SPR method has unusual advantages like label-free, real-time and high resolutions with less than 10-7 RIU which is not consenting with other sensing methods. Photonic Crystal Fiber (PCF) presents unique features like design elasticity, geometric flexible and extraordinary guiding mechanism which head for better performance contrast conventional optical fibre, Additionally, the presence of air holes gives the possibility to insert multi able materials, that can recognize the interaction of travelling light and materials operatively. Adding the advantages of PCF to the properties of SPR, lead to design very strong and unique devices in different applications. In this paper, the PCF sensor based on SPR technique had been presented. The inner holes of PCF were coated with silver and then filled with air and ethanol. This was achieved theoretically by Finite Element Method (FEM). When the phase-matching condition was achieved at a fixed wavelength, the energy of the core-guided mode is shifted to the plasmon area and a resonant loss peak is observed at this wavelength. The simulated results show that a blue shifting is obtained when the outer air holes of PCF is filling with ethanol while the inner ring is filled with silver nano-particles. The maximum resolution and sensitivity are 5.66*10-4 RIU, 132.3 nm/RIU respectively in the sensing range of air refractive index to ethanol refractive index are obtained. The submitted design could be very useful in many fields like refractive index and temperature sensing applications.
This study aims to investigate the characteristics of optical fiber sensors under X-rays radiation. The Radiation-Induced Absorption (RIA) and Radiation-Induced Refractive-Index Change (RIRIC) in the UV-VIS domain were investigated. Single and multi-mode optical fibers (SMFs & MMFs) have been used for this purpose. The outer diameters of these fibers were reduced from (125 to 50 and 55μm for SMF and MMF respectively) via chemical etching process then dipped into (3 wt % concentration) of germanium (Ge) solution to produce the sensing part of the fibers. Due to the applied X-rays radiation, an attenuation of the spectrum and a redshift in peak wavelength were achieved. Both sensors show good responsivity to the applied radiation and the MMFs sensors showed higher wavelength shifting as compared to SMFs sensors.
In this work, an optical fiber refractive index sensor based on the Fabry-Perot interferometer technique is submitted. Single-mode fibers with different diameters (125, 60, and 50) μm were used. The chemical etching technique is used to reduce the fiber diameters. The sensor heads were immersed into liquids of different refractive indices. Two types of liquids were tested, salty and sugary liquids with different refractive indices. From the obtained results all the sensors have a high linearity and good wavelength and intensity sensitivity. For all tested sensors, the wavelength sensitivity was higher for sensors immersed in salty liquids. The sensitivity is 34338 pm/RIU for sensors with a diameter of 50 μm. The response of changing the intensity is also observed the higher intensity sensitivity is 1116.859 μW/RIU for sensors with a diameter of 125 μm immersed into sugary liquids.
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