Toward the reflectance measurement of micro components

Today, the controls by reflection of optical coatings are most of the time made with flat samples thanks to commercial spectrophotometers. However, components become smaller and more complex, curvature radius of lenses or mirrors are larger, so that measures are not so accurate and sometimes are not possible. Flat samples don’t represent anymore the real reflection ability of the component. So to perform this kind of measurements, special devices are needed. A new means developed by the French Atomic Energy Commission (CEA) is proposed to fill in this gap. This device has a accuracy of 0.06% on flat sample over the 400 nm to 950 nm wavelength range with a spot size of 100 mm. It can measure the reflectance of samples even if their shapes are spherical. We investigate stainless steel balls and optical micro components (mirrors and lens) thanks to the tiny size of the analyzing spot of our reflectometer. Herein we introduce our first results on small optical components and show the limiting factors of our device

Is it possible to check microcomponent coatings?

International audienceOptical microcomponents are increasingly used in laser optical systems because of their many and novel industrial applications. These components are coated in order to enhance their optical performance, but optical characterizations are very difficult due to the shapes and small size. Thus, to perform this kind of measurement, special devices are needed. It is difficult to check component optical responses after manufacturing. Thus a new method, developed by the French Atomic Energy and Alternative Energies Commission, is proposed to fill this gap

A Tool to Characterize the Electrical Influence of the Thermal and Mechanical Behaviors of Materials of Optics for CPV applications

Concentrating Photovoltaics (CPV) field aims to integrate expensive high efficiency multi-junction cells into modules with low cost concentrating optics. The choice of the optics depends on different factors: easiness of fabrication and integration process, added costs, optical efficiency and the profile of the spot uniformity reaching the cell. Indeed, previous work has shown a dependence between electrical performance and spectral and spatial uniformities of the light on the cell. To analyze it, a solar CPV test bench is developed at CEA-INES facilities. Lens and cell temperature can be applied separately, in order to evaluate independently different test conditions, while electrical or optical parameters are recorded. The present work shows how temperature and mechanical variations on first stage concentrating optic affects module performances. Several optics and materials are compared, in order to present the tool capabilities

Quantitative estimation of crazing in sol-gel layers by automated optical microscopy analysis

International audienceThis paper describes how to quantify the scattering that appears in thin films deposited on a flat substrate. The defects appear during the deposition process and are hard to identify from classical optical microscopy pictures due to their small surface and contrast. A new way to probe the microroughness of optical components is described for heterogeneous or large samples (cm2) that requires a statistical analysis of each image over a full mapping of the sample. Due to possible optical misalignment or surface waviness, an automatic adjustment of the optical focus plane was implemented for each image during the surface mapping. In this way, we could measure the scattering using a microscope set-up. The results are linked to diffuse reflection and transmission losses (extinction coefficient k) and several different contributions from the total scattering are identified

Overview of electrical power models for concentrated photovoltaic systems

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Spectrally-resolved measurement of concentrated light distributions for Fresnel lens concentrators

International audienceA test method that measures spectrally resolved irradiance distribution for a concentrator photovoltaic (CPV) optical system is presented. In conjunction with electrical I-V curves, it is a means to visualize and characterize the effects of chromatic aberration and nonuniform flux profiles under controllable testing conditions. The indoor characterization test bench, METHOD (Measurement of Electrical, Thermal and Optical Devices), decouples the temperatures of the primary optical element (POE) and the cell allowing their respective effects on optical and electrical performance to be analysed. In varying the temperature of the POE, the effects on electrical efficiency, focal distance, spectral sensitivity, acceptance angle and multi-junction current matching profiles can be quantified. This work presents the calibration procedures to accurately image the spectral irradiance distribution of a CPV system and a study of system behavior over lens temperature

Final Results of CPVMatch - Concentrating Photovoltaic Modules Using Advanced Technologies and Cells for Highest Efficiencies

The EU-funded project Concentrating Photovoltaic modules using advanced technologies and cells for highest efficiencies (CPVMatch) and its main results will be presented. The collaborative project started in May 2015 with a duration of three and a half years and an EC contribution of 4.95 M€. The consortium consists of four research institutions (Fraunhofer ISE, RSE, CEA, Tecnalia), one University (UPM), two industry partners (AZUR Space Solar Power, AIXTRON) and two SMEs (ASSE, Cycleco) and is coordinated by Fraunhofer ISE. The consortium addresses in their research all topics required for manufacturing of high-efficiency CPV modules. This includes material issues, manufacturing and equipment aspect and production challenges. University and research institutes are working in close co-operation with industry partners in order to ensure fast industrial exploitation of all results within the whole value chain

Final Results of CPVMatch - Concentrating Photovoltaic Modules Using Advanced Technologies and Cells for Highest Efficiencies

The EU-funded project Concentrating Photovoltaic modules using advanced technologies and cells for highest efficiencies (CPVMatch) and its main results will be presented. The collaborative project started in May 2015 with a duration of three and a half years and an EC contribution of 4.95 M€. The consortium consists of four research institutions (Fraunhofer ISE, RSE, CEA, Tecnalia), one University (UPM), two industry partners (AZUR Space Solar Power, AIXTRON) and two SMEs (ASSE, Cycleco) and is coordinated by Fraunhofer ISE. The consortium addresses in their research all topics required for manufacturing of high-efficiency CPV modules. This includes material issues, manufacturing and equipment aspect and production challenges. University and research institutes are working in close co-operation with industry partners in order to ensure fast industrial exploitation of all results within the whole value chain