High-Pass Optical Filters Based on Gold-Coated Nanochannel Glass Materials

1996 ◽  
Vol 431 ◽  
Author(s):  
A. Rosenberg ◽  
R. J. Tonucci
Keyword(s):  
Near Infrared ◽  
Optical Filters ◽  
Transmission Peak ◽  
Cutoff Wavelength ◽  
Transmission Spectra ◽  
Channel Diameter ◽  
Resonant Transmission ◽  
Ir Transmission ◽  
Peak Transmission ◽  
High Pass

AbstractWe have fabricated high-pass optical filters from thin nanochannel glass (NCG) wafers coated with sputtered and evaporated gold films. The near-infrared (IR) transmission spectra of these filters have a sharp cutoff at a wavelength that scales linearly with the channel diameter, as expected for hollow metallic waveguides. Cutoff wavelengths approaching 1 μm have been achieved to date using NCG materials with sub-micron channel diameters. The spectra are dominated by a strongly resonant transmission peak just above the cutoff wavelength, where the peak transmission can be as much as twice that predicted based on the geometrical open area of the NCG structure. The NCG wafers were typically less than 20 μm thick, and the Au films ranged in thickness up to 600 nm.

scholarly journals Spectral Irradiance Influence on Solar Cells Efficiency

Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5017
Author(s):  
David Leitão ◽  
João Paulo N. Torres ◽  
João F. P. Fernandes
Keyword(s):  
Near Infrared ◽  
Spectral Response ◽  
Experimental Tests ◽  
Optical Filters ◽  
Spectral Irradiance ◽  
Copper Indium ◽  
Input Variables ◽  
Relative Errors ◽  
The Impact ◽  
High Pass

This paper investigates the influence of the spectral irradiance variation and the spectral response (SR) on the production of energy by photovoltaic cells. To determine the impact of SR and spectral irradiance on m-Si and perovskite cells, experimental tests were conducted outdoors, used optical filters to select different zones of the spectrum. For the computational simulations of the different photovoltaic modules, when subjected to a certain spectral irradiance, a model with spectral factor (SF) was implemented. The SF model accurately simulated the experiments performed for the high-pass filters. The highest relative errors for certain irradiation bands occurred due to the input variables used in the model, which did not fully describe the reality of the experiments performed. The effect of the SR and the spectral irradiance for each of them were observed through the simulations for the m-Si, a-Si, CdTe, and copper indium selenide (CIS) modules. The CIS technology presented a better overall result in the near infrared zone, producing about half of the energy produced by the CdTe technology in the visible zone. The SF, spectral incompatibility factor (MM), and spectral effective responsivity (SEF) parameters were verified to be important for studying the photovoltaic energy production.

Energy efficiency of near infrared cobalt luminscence in ZnSe:Co determined by a photoacoustic method

2012 ◽  
Vol 20 (1) ◽  
Author(s):  
Ł. Chrobak ◽  
M. Maliński ◽  
K. Strzałkowski ◽  
J. Zakrzewski
Keyword(s):  
Energy Efficiency ◽  
Frequency Dependence ◽  
Near Infrared ◽  
Transmission Spectra ◽  
Photoacoustic Method ◽  
Infrared Luminescence ◽  
Amplitude Characteristics

AbstractThe paper presents results of computations of the energy efficiency of the cobalt luminescence in ZnSe:Co determined by the photoacoustic method. The transmission spectra, photoacoustic experimental and theoretical spectra, and the frequency dependence on the photoacoustic amplitude characteristics are presented. From them, the energy efficiency of Co2+ the near infrared luminescence (3200 nm) was computed in the frame of new proposed photoacoustic model of computations of the luminescence energy efficiency.

scholarly journals ANÁLISIS DE COMPONENTES PRINCIPALES DE IMÁGENES MULTIESPECTRALES EN EL ÁMBITO DEL ARTE RUPESTRE

2017 ◽  
Author(s):  
Berta Carrión-Ruiz ◽  
José Luis Lerma
Keyword(s):  
Principal Component Analysis ◽  
Near Infrared ◽  
Rock Art ◽  
Visible Region ◽  
Principal Component ◽  
Optical Filters ◽  
Infrared Region ◽  
Spectral Behaviour ◽  
Near Infrared Region ◽  
Art Analysis

This paper tackles principal component analysis (PCA) in images that include wavelengths between 380-1000 nm. Our approach is focussed on taking advantage of the potencial of ultraviolet and infrarred images, in combination with the visible ones, to improve documentation process and rock art analysis. In this way, we want to improve the discrimination between pigment and support rock, and analyse the spectral behaviour of rock art paintings in the ultraviolet and infrared regions. Three images were used, one image from the ultraviolet (UV) region, one from the visible region (VIS) and another one from the near infrared region (NIR). Optical filters coupled to the camera optics were used to take the images. These filters capture specific wavelengths excluding radiation that we are not interested in registering. Finally, PCA is applied to the acquired images. The results obtained demonstrate the PCA usefulness with imagery in this field and also it is possible to extract some conclusions about the correspondent paint pigments.http://dx.doi.org/10.4995/CIGeo2017.2017.6597

Measurement of the Irganox Content in Polypropylene Polymers during Extrusion

2005 ◽  
Vol 13 (3) ◽  
pp. 147-154 ◽  
Author(s):  
Wolfgang Becker ◽  
Norbert Eisenreich
Keyword(s):  
Near Infrared ◽  
Prediction Models ◽  
Partial Least Square ◽  
Least Square ◽  
Partial Least Square Regression ◽  
Process Conditions ◽  
Transmission Spectra ◽  
Mean Square ◽  
Score Plot ◽  
Least Square Regression

Near infrared spectroscopy was used as an in-line control system for the measurement of polypropylene filled with different amounts of Irganox additives. For this purpose transmission probes were installed in an extruder. The probes can withstand temperatures up to 300°C and pressures up to 60 MPa. Transmission spectra of polypropylene mixed with an Irganox additive were recorded. PCA score plot was carried out revealing the influence of varying conditions for the mixing of the sample preparation. Prediction models were generated with partial least square regression which resulted in a model which estimated Irganox with a coefficient of detremination of 0.984 and a root mean square error of prediction of 0.098%. Furthermore the possibilities for controlling process conditions by measuring transmission at a specific wavelength were shown.

scholarly journals Light Concentration by Metal-Dielectric Micro-Resonators for SERS Sensing

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 103 ◽  
Author(s):  
Andrey Sarychev ◽  
Andrey Ivanov ◽  
Andrey Lagarkov ◽  
Grégory Barbillon
Keyword(s):  
Quantum Electrodynamics ◽  
Near Infrared ◽  
Super Resolution ◽  
Optical Filters ◽  
Energy Concentration ◽  
Plasmonic Structures ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering ◽  
Super Resolution Microscopy ◽  
Sers Sensing

Metal-dielectric micro/nano-composites have surface plasmon resonances in visible and near-infrared domains. Excitation of coupled metal-dielectric resonances is also important. These different resonances can allow enhancement of the electromagnetic field at a subwavelength scale. Hybrid plasmonic structures act as optical antennae by concentrating large electromagnetic energy in micro- and nano-scales. Plasmonic structures are proposed for various applications such as optical filters, investigation of quantum electrodynamics effects, solar energy concentration, magnetic recording, nanolasing, medical imaging and biodetection, surface-enhanced Raman scattering (SERS), and optical super-resolution microscopy. We present the review of recent achievements in experimental and theoretical studies of metal-dielectric micro and nano antennae that are important for fundamental and applied research. The main impact is application of metal-dielectric optical antennae for the efficient SERS sensing.

Remediation of Wastewater from Chlorpyrifos Pesticide by Nano-Gold Photocatalyst

MRS Advances ◽  
2020 ◽  
Vol 5 (52-53) ◽  
pp. 2661-2667 ◽  
Author(s):  
Puja Goel ◽  
Manju Arora
Keyword(s):  
Functional Group ◽  
Localized Surface Plasmon ◽  
Surface Plasmon Resonance Peak ◽  
Transmission Spectra ◽  
Plasmon Resonance Peak ◽  
Color Changes ◽  
Nano Gold ◽  
Absorption Studies ◽  
Ir Transmission ◽  
Nanogold Particles

AbstractSuccessful disintegration of Chlorpyrifos pesticide by nearly monodisperse nano-gold photcatalyst (∼10 nm) for remediation of wastewater has been reported in current studies. Nano-Gold dispersion reaction with Chlorpyrifos solutions completes in 45 minutes at ambient temperature under the normal daylight and exhibit systematic variations in the solution color from wine red to pink to light sky blue and finally transforming into a transparent solution with fine precipitates. UV-Vis absorption studies correlates well with the systematic color changes as observed in the nano-gold treated Chlorpyrifos solutions with time. The characteristic localized surface plasmon resonance peak of nanogold dispersion observed at 529 nm red shifts to weak, medium and strong intensity peaks at ∼ 640 nm, 740 nm and 890 nm on increasing chlorpyrifos concentration owing to the aggregation of gold nanoparticles in small to bigger sized clusters. The fine turbidity in final transparent solution further confirms the aggregation of nanogold particles into stable bigger ensembles. IR transmission spectra of final transparent solutions showed disappearance of Chlorpyrifos νC-Cl and phosphorothioate functional group peaks indicating degradation of chlorpyrifos.

scholarly journals Development and Validation of a Smartphone-Based Near-Infrared Optical Imaging Device to Measure Physiological Changes In-Vivo

Micromachines ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 180 ◽  
Author(s):  
Kacie Kaile ◽  
Anuradha Godavarty
Keyword(s):  
Near Infrared ◽  
Optical Power ◽  
Optical Filters ◽  
Noise Removal ◽  
Light Sources ◽  
Decomposition Algorithms ◽  
Physiological Changes ◽  
Imaging Device ◽  
Nir Imaging

Smartphone-based technologies for medical imaging purposes are limited, especially when it involves the measurement of physiological information of the tissues. Herein, a smartphone-based near-infrared (NIR) imaging device was developed to measure physiological changes in tissues across a wide area and without contact. A custom attachment containing multiple multi-wavelength LED light sources (690, 800, and 840 nm; and <4 mW of optical power per LED), source driver, and optical filters and lenses was clipped onto a smartphone that served as the detector during data acquisition. The ability of the device to measure physiological changes was validated via occlusion studies on control subjects. Noise removal techniques using singular value decomposition algorithms effectively removed surface noise and distinctly differentiated the physiological changes in response to occlusion. In the long term, the developed smartphone-based NIR imaging device with capabilities to capture physiological changes will be a great low-cost alternative for clinicians and eventually for patients with chronic ulcers and bed sores, and/or in pre-screening for potential ulcers in diabetic subjects.

scholarly journals Self-Filtering Monochromatic Infrared Detectors Based on Bi2Se3 (Sb2Te3)/Silicon Heterojunctions

Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1771
Author(s):  
Xujie Pan ◽  
Jing He ◽  
Lei Gao ◽  
Handong Li
Keyword(s):  
Response Time ◽  
Infrared Detectors ◽  
Near Infrared ◽  
Nir Light ◽  
Photoelectric Properties ◽  
Detection Response ◽  
Silicon Heterojunctions ◽  
Surface Modified ◽  
High Pass ◽  
Back Illuminated

This paper focuses on the photoelectric properties of heterostructures formed by surface-modified Si (111) and hexagonal, quintuple-layered selenides (Bi2Se3 and Sb2Te3). It was shown that H-passivated Si (111) can form robust Schottky junctions with either Bi2Se3 or Sb2Te3. When back illuminated (i.e., light incident towards the Si side of the junction), both the Bi2Se3/Si and Sb2Te3/Si junctions exhibited significant photovoltaic response at 1030 nm, which is right within the near-infrared (NIR) light wavelength range. A maximum external quantum efficiency of 14.7% with a detection response time of 2 ms for Bi2Se3/Si junction, and of 15.5% with a 0.8 ms response time for the Sb2Te3/Si junction, were achieved. Therefore, utilizing Si constituents as high-pass filters, the Bi2Se3 (Sb2Te3)/Si heterojunctions can serve as monochromatic NIR photodetectors.

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