Topographic optical profilometry by absorption in liquids

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Optical absorbance within a liquid is used as a photometric probe to measure the topography of optical surfaces relative to a reference. The liquid fills the gap between the reference surface and the measuring surface. By comparing two transmission images at different wavelengths we can profile the height distribution in a simple and reliable way. The presented method handles steep surface slopes (<90 degrees) without difficulty. It adapts well to any field of view and height range (peak to valley). A height resolution in the order of the nanometer may be achieved and the height range can be tailored by adapting the concentration of water soluble dyes. It is especially appropriate for 3D profiling of transparent complex optical surfaces, like those found in micro-optic arrays and for Fresnel, aspheric or free-form lenses, which are very difficult to measure by other optical methods. We show some experimental results to validate its capabilities as a metrological tool and handling of steep surface slopes.
© 2012 Optical Society of America. This work has been developed within the framework of the project DPI2009-09023 financially supported by Spanish MICINN (Ministerio de Ciencia e Innovación).
1. K. P. Thompson and J. P. Rolland, “A revolution in imaging optical design,” Opt. Photon. News 23(6), 30–35 (2012). 2. C. C. Lai and I. J. Hsu, “Surface profilometry with composite interferometer,” Opt. Express 15(21), 13949–13956 (2007). 3. L. Deck and P. de Groot, “High-speed noncontact profiler based on scanning white-light interferometry,” Appl. Opt. 33(31), 7334–7338 (1994). 4. J. C. Wyant, “Advances in interferometric surface measurement,” Proc. SPIE 6024, 602401, 602401-11 (2006). 5. C. Zhao, J. Tan, J. Tang, T. Liu, and J. Liu, “Confocal simultaneous phase-shifting interferometry,” Appl. Opt. 50(5), 655–661 (2011). 6. C. H. Lee, H. Y. Mong, and W. C. Lin, “Noninterferometric wide-field optical profilometry with nanometer depth resolution,” Opt. Lett. 27(20), 1773–1775 (2002). 7. F. Blais, “Review of 20 years of range sensor development,” J. Electron. Imaging 13(1), 231–243 (2004). 8. F. Chen, G. M. Brown, and M. Song, “Overview of three-dimensional shape measurement using optical methods,” Opt. Eng. 39(1), 10–22 (2000). 9. D. Purcell, A. Suratkar, A. Davies, F. Farahi, H. Ottevaere, and H. Thienpont, “Interferometric technique for faceted microstructure metrology using an index matching liquid,” Appl. Opt. 49(4), 732–738 (2010). 10. G. Svensson, “A method for measurement of the absorption in extremely high-absorbing solutions,” Exp. Cell Res. 9(3), 428–433 (1955). 11. M. Csete and Z. Bor, “Plano-concave microcuvette for measuring the absorption coefficient of highly absorbing liquids,” Appl. Opt. 36(10), 2133–2138 (1997). 12. J. Johnson and T. Harris, “Full-field optical thickness profilometry of semitransparent thin films with transmission densitometry,” Appl. Opt. 49(15), 2920–2928 (2010). 13. S. Ogilvie, E. Isakov, C. Taylor, and P. Glover, “A new high resolution optical method for obtaining the topography of fracture surfaces in rocks,” Image Anal. Stereol. 21(1), 61–66 (2002). 14. E. Isakov, S. R. Ogilvie, C. W. Taylor, and P. W. J. Glover, “Fluid flow through rough fractures in rocks 1: high resolution aperture determinations,” Earth Planet. Sci. Lett. 191(3-4), 267–282 (2001). 15. M. A. Model, A. K. Khitrin, and J. L. Blank, “Measurement of the absorption of concentrated dyes and their use for quantitative imaging of surface topography,” J. Microsc. 231(1), 156–167 (2008). 16. J. C. Martínez Antón, J. A. Gómez Pedrero, J. Alonso Fernández, and J. A. Quiroga, “Optical method for the surface topographic characterization of Fresnel lenses,” Proc. SPIE 8169, 816910-8 (2011).