Thin film absorption characterization by focus error thermal lensing
A simple, highly sensitive technique for measuring absorbed power in thin film dielectrics based on thermal lensing is demonstrated. Absorption of an amplitude modulated or pulsed incident pump beam by a thin film acts as a heat source that induces thermal lensing in the substrate. A second continuo...
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2017
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00346748_v88_n12_p_Domene http://hdl.handle.net/20.500.12110/paper_00346748_v88_n12_p_Domene |
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paper:paper_00346748_v88_n12_p_Domene |
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paper:paper_00346748_v88_n12_p_Domene2025-07-30T17:41:40Z Thin film absorption characterization by focus error thermal lensing Dielectric materials Errors Film growth Fused silica Optical pumping Probes Silica Substrates Amplitude modulated Dielectric thin films Focus error signal Four quadrant detectors Fused silica substrates Noise contributions Sensitive techniques Thin-film dielectrics Thin films A simple, highly sensitive technique for measuring absorbed power in thin film dielectrics based on thermal lensing is demonstrated. Absorption of an amplitude modulated or pulsed incident pump beam by a thin film acts as a heat source that induces thermal lensing in the substrate. A second continuous wave collimated probe beam defocuses after passing through the sample. Determination of absorption is achieved by quantifying the change of the probe beam profile at the focal plane using a four-quadrant detector and cylindrical lenses to generate a focus error signal. This signal is inherently insensitive to deflection, which removes noise contribution from point beam stability. A linear dependence of the focus error signal on the absorbed power is shown for a dynamic range of over 105. This technique was used to measure absorption loss in dielectric thin films deposited on fused silica substrates. In pulsed configuration, a single shot sensitivity of about 20 ppm is demonstrated, providing a unique technique for the characterization of moving targets as found in thin film growth instrumentation. © 2017 Author(s). 2017 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00346748_v88_n12_p_Domene http://hdl.handle.net/20.500.12110/paper_00346748_v88_n12_p_Domene |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Dielectric materials Errors Film growth Fused silica Optical pumping Probes Silica Substrates Amplitude modulated Dielectric thin films Focus error signal Four quadrant detectors Fused silica substrates Noise contributions Sensitive techniques Thin-film dielectrics Thin films |
| spellingShingle |
Dielectric materials Errors Film growth Fused silica Optical pumping Probes Silica Substrates Amplitude modulated Dielectric thin films Focus error signal Four quadrant detectors Fused silica substrates Noise contributions Sensitive techniques Thin-film dielectrics Thin films Thin film absorption characterization by focus error thermal lensing |
| topic_facet |
Dielectric materials Errors Film growth Fused silica Optical pumping Probes Silica Substrates Amplitude modulated Dielectric thin films Focus error signal Four quadrant detectors Fused silica substrates Noise contributions Sensitive techniques Thin-film dielectrics Thin films |
| description |
A simple, highly sensitive technique for measuring absorbed power in thin film dielectrics based on thermal lensing is demonstrated. Absorption of an amplitude modulated or pulsed incident pump beam by a thin film acts as a heat source that induces thermal lensing in the substrate. A second continuous wave collimated probe beam defocuses after passing through the sample. Determination of absorption is achieved by quantifying the change of the probe beam profile at the focal plane using a four-quadrant detector and cylindrical lenses to generate a focus error signal. This signal is inherently insensitive to deflection, which removes noise contribution from point beam stability. A linear dependence of the focus error signal on the absorbed power is shown for a dynamic range of over 105. This technique was used to measure absorption loss in dielectric thin films deposited on fused silica substrates. In pulsed configuration, a single shot sensitivity of about 20 ppm is demonstrated, providing a unique technique for the characterization of moving targets as found in thin film growth instrumentation. © 2017 Author(s). |
| title |
Thin film absorption characterization by focus error thermal lensing |
| title_short |
Thin film absorption characterization by focus error thermal lensing |
| title_full |
Thin film absorption characterization by focus error thermal lensing |
| title_fullStr |
Thin film absorption characterization by focus error thermal lensing |
| title_full_unstemmed |
Thin film absorption characterization by focus error thermal lensing |
| title_sort |
thin film absorption characterization by focus error thermal lensing |
| publishDate |
2017 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00346748_v88_n12_p_Domene http://hdl.handle.net/20.500.12110/paper_00346748_v88_n12_p_Domene |
| _version_ |
1840327489949270016 |