Details
| Original language | English |
|---|---|
| Article number | 122503 |
| Journal | Optical Engineering |
| Volume | 53 |
| Issue number | 12 |
| Publication status | Published - 1 Jul 2014 |
| Externally published | Yes |
Abstract
Laser calorimetry is based on the measurement and evaluation of the temperature increase caused by absorption in the sample exposed to laser radiation. A temperature distribution develops in the irradiated sample as a result of dependence on the thermal diffusivity of the sample. Therefore, finding a correlation between the temperature increase and absorption becomes a complex task. This challenge was met by keeping the sample geometry at a standard size and simulating the thermal distribution for a number of optical materials. Using this method, Laser Zentrum Hannover e.V. (LZH) developed a calorimetric test setup that offers fully calibrated absorptance values for sample diameters of 25 mm (or 1 in.) with a total error of below 13% and a relative measurement error of below 5%. However, this technique is limited to the above-mentioned sample geometry. This work presents an approach to adjust the measurement configuration to numerous sample sizes for standard circular laser components. Finite element analysis and experimental verification are presented for exemplary values of the samples' diameters. Based on the different sample mount concept, this procedure allows utilizing flexibility in test wavelength and angle of incidence, combined with the sensitivity level sufficient for current optical materials.
Keywords
- absorption, contamination, high power laser, laser calorimetry, metrology, optical thin films, substrates, ultrafast laser optics
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Atomic and Molecular Physics, and Optics
- Engineering(all)
- General Engineering
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In: Optical Engineering, Vol. 53, No. 12, 122503, 01.07.2014.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Laser calorimetric absorptance testing of samples with varying geometry
AU - Balasa, Istvan
AU - Jensen, Lars O.
AU - Ristau, Detlev
PY - 2014/7/1
Y1 - 2014/7/1
N2 - Laser calorimetry is based on the measurement and evaluation of the temperature increase caused by absorption in the sample exposed to laser radiation. A temperature distribution develops in the irradiated sample as a result of dependence on the thermal diffusivity of the sample. Therefore, finding a correlation between the temperature increase and absorption becomes a complex task. This challenge was met by keeping the sample geometry at a standard size and simulating the thermal distribution for a number of optical materials. Using this method, Laser Zentrum Hannover e.V. (LZH) developed a calorimetric test setup that offers fully calibrated absorptance values for sample diameters of 25 mm (or 1 in.) with a total error of below 13% and a relative measurement error of below 5%. However, this technique is limited to the above-mentioned sample geometry. This work presents an approach to adjust the measurement configuration to numerous sample sizes for standard circular laser components. Finite element analysis and experimental verification are presented for exemplary values of the samples' diameters. Based on the different sample mount concept, this procedure allows utilizing flexibility in test wavelength and angle of incidence, combined with the sensitivity level sufficient for current optical materials.
AB - Laser calorimetry is based on the measurement and evaluation of the temperature increase caused by absorption in the sample exposed to laser radiation. A temperature distribution develops in the irradiated sample as a result of dependence on the thermal diffusivity of the sample. Therefore, finding a correlation between the temperature increase and absorption becomes a complex task. This challenge was met by keeping the sample geometry at a standard size and simulating the thermal distribution for a number of optical materials. Using this method, Laser Zentrum Hannover e.V. (LZH) developed a calorimetric test setup that offers fully calibrated absorptance values for sample diameters of 25 mm (or 1 in.) with a total error of below 13% and a relative measurement error of below 5%. However, this technique is limited to the above-mentioned sample geometry. This work presents an approach to adjust the measurement configuration to numerous sample sizes for standard circular laser components. Finite element analysis and experimental verification are presented for exemplary values of the samples' diameters. Based on the different sample mount concept, this procedure allows utilizing flexibility in test wavelength and angle of incidence, combined with the sensitivity level sufficient for current optical materials.
KW - absorption
KW - contamination
KW - high power laser
KW - laser calorimetry
KW - metrology
KW - optical thin films
KW - substrates
KW - ultrafast laser optics
UR - http://www.scopus.com/inward/record.url?scp=84940258703&partnerID=8YFLogxK
U2 - 10.1117/1.oe.53.12.122503
DO - 10.1117/1.oe.53.12.122503
M3 - Article
AN - SCOPUS:84940258703
VL - 53
JO - Optical Engineering
JF - Optical Engineering
SN - 0091-3286
IS - 12
M1 - 122503
ER -