Calibration accuracy of laser calorimetry for common crystal geometries
| Autor: | Willer, Yannick, Hao, Liu, Balasa, Istvan, Ristau, Detlev, Exarhos, Gregory J., Gruzdev, Vitaly E., Menapace, Joseph A., Soileau, M.J. |
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| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Finite element method
Materials science Nonlinear optics laser optics Testing Laser calorimetry Geometry Calorimetry Temperature measurement law.invention Absorption ISO11551 Calorimeters Calibration procedure Optics Thermal conductivity law Absorption measurements Calibration ddc:530 Light absorption Absorption (electromagnetic radiation) Propagation direction Calibration accuracy Heat conduction Konferenzschrift Precise determinations Absolute calibration business.industry Laser finite heat conductivity Optical materials Dewey Decimal Classification::500 | Naturwissenschaften::530 | Physik business Laser damage Beam (structure) |
| Zdroj: | Proceedings of SPIE 10447 (2017) |
| DOI: | 10.15488/3310 |
| Popis: | An established method for precise determination of optical absorption is the so called laser calorimetry. According to ISO 115511 laser calorimetry is preferred to other photothermal test methods, because of its capability to deliver absolute calibration. Many optical materials have low heat conductivity, which can affect the calibration significantly. The timeand spatial dependent temperature profile in a sample of materials with low heat conductivity requires accurate temperature measurement strategies to determine material-independent and absolutely calibrated absorption values. For thin cylindrical samples, ISO 11551 provides a strategy to compensate heat conductivity effects. The optimal temperature sensor position, where accordingly calibrated measurement results2 can be obtained, is simply based on the symmetric sample geometry. For thick geometries an additional temperature distribution along propagation direction of the heating beam must be considered. The current version of ISO 11551 does not provide a sophisticated solution for this problem, because the heating scheme of a sample is usually unknown. Therefore, a reliable calibration procedure can only be applied to samples of well-known absorption properties of surfaces and bulk material. Utilizing such kind of specifically prepared reference samples in combination with Finite Element Method (FEM) calculations, a general measurement and data evaluation concept based on laser calorimetry is presented, that allows deriving absolutely calibrated absorption measurement results for rectangular sample geometries. © 2017 SPIE. |
| Databáze: | OpenAIRE |
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