Comparison of three focus sensors for optical topography measurement of rough surfaces
| Autor: | Josef Lazar, Jindřich Oulehla, Tomáš Fořt, Miroslava Holá, Petr Schovanek, Martin Šarbort, Jan Pavelka, Šimon Řeřucha |
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| Rok vydání: | 2019 |
| Předmět: |
White light interferometry
Spatial light modulator Materials science business.industry 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Atomic and Molecular Physics and Optics 010309 optics Axicon Speckle pattern Optics 0103 physical sciences Surface roughness Prism Monochromatic color 0210 nano-technology business Focus (optics) |
| Zdroj: | Optics Express. 27:33459 |
| ISSN: | 1094-4087 |
| Popis: | The study compares three variants of focus sensors designed for the optical topography measurement of rough surface specimens with submicron accuracy. We present a theoretical analysis of the focus sensor principles and the experimental measurements with a single point laser probe. A low coherent illumination beam was provided by a monochromatic laser source and a rotating diffuser, which reduced the speckles generated by the rough surface. The reflected beam was modulated by three specific optical elements (axicon, double wedge prism, four spherical lenses) realized by a spatial light modulator. A digital camera detected the output intensity patterns that were evaluated by the intensity centroid method. The results showed a good coincidence of the surface profiles obtained by the three sensor variants with the root-mean-square deviations below one micron. We discuss the results obtained for several specimens with various surface roughness and compare the differences between the three focus sensor variants. |
| Databáze: | OpenAIRE |
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