Point Focus Solar Spectral Splitting System for CPV Applications

2013 ◽  
Vol 1493 ◽  
pp. 65-69
Author(s):  
Ahmed Zayan ◽  
Matteo Chiesa ◽  
Marco Stefancich
Keyword(s):  
Visible Region ◽  
Optical Element ◽  
Ambient Air ◽  
Merit Function ◽  
Index Of Refraction ◽  
Mathematical Framework ◽  
Angle Of Incidence ◽  
Prismatic Structure ◽  
Current Matching ◽  
Spectral Splitting

ABSTRACTSolar spectral splitting technologies have been investigated over the years as alternatives to improve the efficiencies obtained from photovoltaic devices by splitting the incident solar light into its respective wavelengths, and aligning a series of photovoltaic cells arranged next to each other as opposed to being physically stacked on top of each other as is the case with multijunction cells. Limitations previously posed by multijunction cells like current matching and lattice matching are circumvented through this approach, allowing for a broader and potentially cheaper pool of candidate cells to be used for energy conversion. In this study, we design and gauge the performance of a single optical element capable of splitting the light and concentrating it simultaneously unto a bed of photovoltaics, each illuminated by the part of the spectrum that corresponds best to its relevant properties such as the bandgap and the external quantum efficiency. The prismatic structure constituting the device relies on the device’s transmission in the visible region and its dispersion. Presented in this study is the mathematical framework used in designing the structure for a specific merit function; in particular, the study focuses on minimizing optical losses at the interfaces of the structure with the ambient air. Variables like the index of refraction of the material used, the angle of incidence on the surface, the exit angle of the light out of the structure factor into the optical center’s design. Compared to alternative splitting technologies like dichroic mirrors, the model splits the incident polychromatic light into a continuous band of wavelengths as opposed to discrete wavelengths that can be adapted on to different sets of single junction cells. The device is an improvement to our published 1-axis linear concentrator reported earlier in the year for its point-focus output yielding in even higher concentration and potentially lowers costs.

X. On the action of the second surfaces of transparent plates upon light

1830 ◽  
Vol 120 ◽  
pp. 145-152 ◽  
Keyword(s):  
Index Of Refraction ◽  
Angle Of Incidence ◽  
Remarkable Result ◽  
The Law ◽  
Polarization Of Light

In a paper on the Polarization of Light by Reflexion, published in the Philosophical Transactions for 1815, I showed that the Law of the Tangents was rigorously true for the second surfaces of transparent bodies, provided that the sine of the angle of incidence was less than the reciprocal of the index of refraction. The action of the second surfaces of plates at angles of incidence different from the maximum polarizing angle, was studied by M. Arago, who conducted his experiments in the following manner. “With respect to this phænomenon,” says M. Arago, “a remarkable result of experiment may here be noticed; that is, that in every possible inclination A = A'.

scholarly journals Ambient Air Quality Classification by Grey Wolf Optimizer Based Support Vector Machine

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Akash Saxena ◽  
Shalini Shekhawat
Keyword(s):  
Support Vector Machine ◽  
Air Quality ◽  
Industrial Development ◽  
Learning Algorithm ◽  
Ambient Air ◽  
Support Vector ◽  
Grey Wolf Optimizer ◽  
Mathematical Framework ◽  
Primary Concern

With the development of society along with an escalating population, the concerns regarding public health have cropped up. The quality of air becomes primary concern regarding constant increase in the number of vehicles and industrial development. With this concern, several indices have been proposed to indicate the pollutant concentrations. In this paper, we present a mathematical framework to formulate a Cumulative Index (CI) on the basis of an individual concentration of four major pollutants (SO2, NO2, PM2.5, and PM10). Further, a supervised learning algorithm based classifier is proposed. This classifier employs support vector machine (SVM) to classify air quality into two types, that is, good or harmful. The potential inputs for this classifier are the calculated values of CIs. The efficacy of the classifier is tested on the real data of three locations: Kolkata, Delhi, and Bhopal. It is observed that the classifier performs well to classify the quality of air.

Diffractive Spectral-Splitting Optical Element Designed by Adjoint-Based Electromagnetic Optimization and Fabricated by Femtosecond 3D Direct Laser Writing

ACS Photonics ◽  
2016 ◽  
Vol 3 (5) ◽  
pp. 886-894 ◽  
Author(s):  
T. Patrick Xiao ◽  
Osman S. Cifci ◽  
Samarth Bhargava ◽  
Hao Chen ◽  
Timo Gissibl ◽  
...  
Keyword(s):  
Optical Element ◽  
Direct Laser Writing ◽  
Laser Writing ◽  
Direct Laser ◽  
Spectral Splitting

Preparation and Characterization of Cu-Doped Zno Sol-Gel Derived Optical Thin Films

2013 ◽  
Vol 802 ◽  
pp. 124-128 ◽  
Author(s):  
Krisana Chongsri ◽  
Siriwattana Aunpang ◽  
Wicharn Techitdheera ◽  
Wisanu Pecharapa
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Sol Gel ◽  
Copper Acetate ◽  
Visible Region ◽  
Ambient Air ◽  
Doping Content ◽  
Acetate Dihydrate ◽  
Cu Doping ◽  
Doped Zno

In this work, we report the preparation of Cu-doped ZnOthin films by sol-gel method based on zinc acetate dihydrate (CH3COO)2Zn·2H2O, Copper acetate dihydrate Cu3(CH3COO)2·H2O) and diethanolamine (HN(CH2OH)2, DEA). The precursor solution was prepared at various Cu composition ranging from 2-20 wt%. All films were spin-coated on borosilicate substrates for several coating repetition followed by annealing process at 550 °C for 4 h in an ambient air. The structural properties of the films were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The XRD results indicate the domination of hexagonal wurtzite structure of ZnO with noticeable alternation in the XRD peak intensity upon Cu doping content. SEM results revealed the grain size shape and surface morphologies of as-prepared samples. Crucial optical properties of as-prepared films were scrutinized from their UV-Vis transmission spectra. The films are highly transparent in the visible region with more than 90 % transparency within 380 nm to 800 nm. Their corresponding band gaps indicate significant red shift with increasing Cu doping content. Overall results suggest that Cu additive play a vital role on relevant optical properties of ZnO that can be adjusted to meet the requirement for practical optoelectronics applications.

A simple optical system delivering a tunable micrometer pink beam that can compensate for heat-induced deformations

2015 ◽  
Vol 22 (4) ◽  
pp. 930-935 ◽  
Author(s):  
Ruben Reininger ◽  
Zunping Liu ◽  
Gilles Doumy ◽  
Linda Young
Keyword(s):  
Optical System ◽  
Heat Load ◽  
Optical Element ◽  
High Energy ◽  
Angle Of Incidence ◽  
Optical Elements ◽  
Source Distance ◽  
Energy Cutoff ◽  
Working Distance ◽  
Photon Source

The radiation from an undulator reflected from one or more optical elements (usually termed `pink-beam') is used in photon-hungry experiments. The optical elements serve as a high-energy cutoff and for focusing purposes. One of the issues with this configuration is maintaining the focal spot dimension as the energy of the undulator is varied, since this changes the heat load absorbed by the first optical element. Finite-element analyses of the power absorbed by a side water-cooled mirror exposed to the radiation emitted by an undulator at the Advanced Photon Source (APS) and at the APS after the proposed upgrade (APSU) reveals that the mirror deformation is very close to a convex cylinder creating a virtual source closer to the mirror than the undulator source. Here a simple optical system is described based on a Kirkpatrick–Baez pair which keeps the focus size to less than 2 µm (in the APSU case) with a working distance of 350 mm despite the heat-load-induced change in source distance. Detailed ray tracings at several photon energies for both the APS and APSU show that slightly decreasing the angle of incidence on the mirrors corrects the change in the `virtual' position of the source. The system delivers more than 70% of the first undulator harmonic with very low higher-orders contamination for energies between 5 and 10 keV.

Ellipsometric Characterization for Multilayers Containing Magneto-Optic TbFeCo Films

1987 ◽  
Vol 103 ◽  
Author(s):  
M. Ruane ◽  
A. Jain
Keyword(s):  
Optical Activity ◽  
Optical Signal ◽  
Optically Active ◽  
Index Of Refraction ◽  
Dielectric Tensor ◽  
Angle Of Incidence ◽  
Multilayered Structures ◽  
Kerr Rotation ◽  
Ellipsometric Characterization ◽  
Sputter Deposited

ABSTRACTMultilayered structures containing sputter-deposited films of amorphous TbFeCo can exhibit magneto-optical Kerr rotation and are leading candidates for erasable optical storage media. Ellipsometric characterization of optically active multilayered media is desirable during media development, testing and production, but traditional ellipsometry does not account for the presence of optical activity. A novel ellipsometer is described that can characterize both the dielectric overcoat and the optically active layers. Reflectivity measurements are collected for different incident angles and polarizations using a differential detector while the magnetic reversibility of the active film layer is exploited to enhance the magneto-optical signal from the TbFeCo. A multilayer film model is used to process observations and estimate media characteristics. The model explicitly accounts for the optical activity of the TbFeCo layer, and is parameterized in terms of the index of refraction and thickness of the overcoat, and the real and imaginary parts of the elements of the dielectric tensor of the active layer.A series of TbFeCo films with varying composition, rf-sputter deposited on quartz substrates with Al2O3 dielectric protective overcoats, is characterized. Both Tb-rich and Fe-rich samples were deposited, with room temperature coercivities ranging from 1.6kOe to about 4kOe, and film-side Kerr rotations between 21 minutes and 28 minutes. Reflectivity data versus angle of incidence, and estimated dielectric tensor elements for the TbFeCo layers are presented. A standard figure of merit, based on the off-diagonal tensor elements, is used to compare competing media in terms of their optimal performance in a multilayered structure.

Superlattice Optical Properties Measured by Variable Angle Spectroscopic Ellipsometry

1987 ◽  
Vol 102 ◽  
Author(s):  
P. G. Snyder ◽  
K. G. Merkel ◽  
B. N. De ◽  
J. A. Woollam ◽  
D. W. Langer ◽  
...  
Keyword(s):  
Spectroscopic Ellipsometry ◽  
Room Temperature ◽  
Optical Constants ◽  
Nondestructive Method ◽  
Effective Index ◽  
Index Of Refraction ◽  
Angle Of Incidence ◽  
Variable Angle ◽  
Superlattice Layer ◽  
Effective Index Of Refraction

ABSTRACTVariable Angle of incidence Spectroscopic Ellipsometry (VASE) is a sensitive, nondestructive method of determining optical constants, layer thicknesses, alloy compositions and other parameters. We model the VASE data for a sample containing a 20 period Al0 5Ga0 5As-GaAs superlattice, to obtain the effective index of refraction (n) and e tinction coefficient (k) of the superlattice layer. The room temperature VASE spectra contain strong, sharp features at the e-hh(1), e-lh(1) and e-hh(2) excitonic tran-sition energies. In addition, VASE was used to characterize more compli-cated layered structures, which also contained superlattices.

scholarly journals Chromium plasmonic polarizer for high intensity light

2017 ◽  
Vol 9 (3) ◽  
pp. 76 ◽  
Author(s):  
Damian Arkadiusz Michalik ◽  
Paweł S. Jung ◽  
Bartłomiej W. Klus ◽  
Andrzej Kowalik ◽  
Anna Rojek ◽  
...  
Keyword(s):  
Thin Film ◽  
High Intensity ◽  
Fdtd Method ◽  
Visible Region ◽  
Visible Spectrum ◽  
Optical Element ◽  
Perfect Absorber ◽  
Wire Grid ◽  
Circuit Components ◽  
Wire Grid Polarizer

In this work, we investigate a thin-film polarizer for a high intensity of the electromagnetic (EM) beam based on Cr nano wire arrays. Commonly used thin-film polarizing components are very sensitive for high power of EM waves and can be easily damaged by focused beams. The solution to this problem could be the thin-film polarizer based on metallic subwavelengths structures. This type of optical element has huge resistance comparing to typical thin-film polarizers. However, designing such an optical element for proper wavelength of EM wave and transmissions is not easy task. In this paper we present numerical as well as experimental results for specially designed chromium thin-film polarizer for wavelength 532nm Full Text: PDF ReferencesW. Zhou, K. Li, C. Song, P. Hao, M. Chi, M. Yu and Y. Wu, "Polarization-independent and omnidirectional nearly perfect absorber with ultra-thin 2D subwavelength metal grating in the visible region", Opt. Express 23, 11 (2015). CrossRef W. L. Barnes, A . Dereux, and T. W. Ebbesen, "Surface plasmon subwavelength optics", Nature 424, 824-830 (2003). CrossRef C. Lee, E. Sim, D. Kim, "Blazed wire-grid polarizer for plasmon-enhanced polarization extinction: design and analysis", Opt. Express 25, 7 (2017). CrossRef A. Lehmuskero, Metallic thin film structures and polarization shaping gratings (University of Eastern Finland 2010).Y. Leroux, J. C. Lacroix, C. Fave, V. Stockhausen, N. Felidj, J. Grandm, A. Hohenau, J. R. Krenn, "Active plasmonic devices with anisotropic optical response: a step toward active polarizer", Nano Lett. 5, 9 (2009). CrossRef R. T. Perkins, D. P. Hansen, E. W. Gardner, J. M. Thorne, A. A. Robbins, Broadband wire grid polarizer for the visible spectrum, US 6122103 (2000). DirectLink D. M. Sullivan, Electromagnetic simulation using the FDTD method, New York: IEEE Press Series (2000). CrossRef J. P. Berenger, Perfectly Matched Layer (PML) for Computational Electromagnetics, Morgan & Claypool Publishers (2007). CrossRef Yu, W., and R. Mittra, "A conformal FDTD software package modeling antennas and microstrip circuit components", IEEE Antennas Propagat. Magazine 42, 28 (2000) . CrossRef L. W. Bos, D. W. Lynch, "Optical Properties of Antiferromagnetic Chromium and Dilute Cr-Mn and Cr-Re Alloys", Phys. Rev. Sect. B, 2, 4267 (1970). CrossRef

scholarly journals Photocurrent modelling and experimental confirmation for Meteor Smoke Particle Detectors onboard atmospheric sounding rockets

2018 ◽  
Author(s):  
Gabriel Giono ◽  
Boris Strelnikov ◽  
Heiner Asmus ◽  
Tristan Staszak ◽  
Nickolay Ivchenko ◽  
...  
Keyword(s):  
Complex Structure ◽  
Index Of Refraction ◽  
Experimental Measurements ◽  
Angle Of Incidence ◽  
Central Electrode ◽  
Particle Detectors ◽  
Detailed Model ◽  
Sounding Rockets ◽  
Smoke Particle ◽  
Order Of Magnitude

Abstract. Characterizing the photoelectron current induced by the Sun’s UV radiation is crucial to ensure accurate daylight measurements from particle detectors. This article lays out the methodology used to address this problem in the case of the Meteor Smoke Particle Detectors (MSPDs), developed by the Leibniz Institute of Atmospheric Physics in Kühlungsborn (IAP) and to be flown onboard the PMWE (Polar Meosphere Winter Echoes) sounding rockets in mid-April 2018. The methodology focuses on two complementary aspects: modelling and experimental measurements. A detailed model of the MSPD photocurrent was created based on the expected solar UV flux, the atmospheric UV absorption as a function of height by molecular oxygen and ozone, the photoelectric yield of the material coating the MSPD as a function of wavelength, the index of refraction of these materials as a function of wavelength and the angle of incidence of the illumination onto the MSPD. Due to its complex structure composed of a central electrode shielded by two concentric grids, extensive ray tracing calculations were conducted to obtain the incidence angles of the illumination on the central electrode, and this for various orientations of the MSPD with respect to the Sun. Results of the modelled photocurrent at different heights and for different materials, as well as for different orientation of the detector, are presented. As a pre-flight confirmation, the model was used to reproduce the experimental measurements conducted by Robertson et. al. (2014) and agrees within an order of magnitude. An experimental setup for the calibration of the MSPD photocurrent is also presented. The photocurrent induced by the Lyman-alpha line from a deuterium lamp was recorded inside a vacuum chamber using a narrow-band filter, while an UV-sensitive photodiode was used to monitor the UV flux. These measurements were compared with the model prediction, and also matched within the same order of magnitude. Although precisely modelling the photocurrent is a challenging task, this article quantitatively improved the understanding of the photocurrent on the MSPD and discusses possible strategies to untangle the MSP current from the photocurrent recorded in-flight.

scholarly journals Effect of thermodenuding on the structure of nascent flame soot aggregates

2016 ◽  
Author(s):  
Janarjan Bhandari ◽  
Swarup China ◽  
Timothy Onasch ◽  
Lindsay Wolff ◽  
Andrew Lambe ◽  
...  
Keyword(s):  
Optical Properties ◽  
Ambient Air ◽  
Organic Coating ◽  
Index Of Refraction ◽  
Morphological Properties ◽  
Soot Particles ◽  
Internal Mixing ◽  
Soot Aggregate ◽  
Before And After ◽  
Particle Level

Abstract. The optical properties (light scattering and absorption) of soot particles depend on soot size and index of refraction, but also on the soot complex morphology and the internal mixing with other material at the single particle level. For example, freshly emitted (nascent) soot particles can interact with other materials in the atmosphere, materials that can condense on soot and coat it. This coating can affect the soot optical properties by refracting light, or by changing the soot aggregate structure. A common approach to studying the effect of coating on soot optical properties is to measure absorption and scattering values in ambient air and then measure them again after removing the coating using a thermodenuder. In this approach, it is assumed that: 1) Most of the coating material is removed; 2) charred organic coating does not add to the refractory carbon; 3) oxidation of soot is negligible; and 4) the pre-existing core soot structure is left unaltered despite potential oxidation of the core at elevated temperature. In this study, we investigate the validity of the last assumption, by studying the effect of thermodenuding on the structure of nascent soot. To this end, we analyze the morphological properties of laboratory generated nascent soot, before and after thermodenuding. Our investigation shows that there is only minor restructuring of nascent soot by thermodenuding.

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