Abstract
Confocal Raman microscopes are widely used in various applications because they provide physical and chemical information at a submicron scale. A high lateral resolution in the confocal Raman microscope is essential for obtaining high-quality images. We used an array of tungsten dots at a 600 nm pitch on a Si substrate of the certified reference material (NMIJ CRM 5207-a) to reliably evaluate the lateral resolution of a confocal Raman microscope at various pinhole sizes. The precision of the mapping scale in the x- and y-pitches was confirmed from Si signal profiles, and the lateral resolution was evaluated by a straight-edge method using scale indicators in the reference material. Because these procedures are applicable to other confocal Raman microscopes with popular specifications (532 nm laser, 100× objective lens, numerical aperture 0.9, step size 0.1 μm), they are suitable for both a reliable evaluation of the lateral resolution of a confocal Raman microscope and for daily checks on the precision of its mapping scale.
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References
R. L. McCreery, “Raman Spectroscopy for Chemical Analysis”, 2000, Wiley Interscience, New York.
I. R. Lewis and H. Edwards, “Handbook of Raman Spectroscopy: From the Research Laboratory to the Process Line (Practical Spectroscopy)”, 2001, CRC Press, New York.
J. R. Ferraro, K. Nakamoto, and C. W. Brown, “Introductory Raman Spectroscopy”, 2nd ed., 2003, Academic Press, Amsterdam.
A. Zoubir, “Raman Imaging: Techniques and Applications”, 2012, Springer, Cham.
J. Toporski, T. Dieing, and O. Hollricher, “Confocal Raman Microscopy”, 2nd ed., 2019, Springer, Cham.
C. F. Araujo, M. M. Nolasco, A. M. P. Ribeiro, and P. J. A. Ribeiro-Claro, Water Res., 2018, 142, 426.
ISO18337:2015, “Surface Chemical Analysis—Surface Characterization—Measurement of the Lateral Resolution of a Confocal Fluorescence Microscope”.
ISO18516:2019, “Surface Chemical Analysis—Determination of Lateral Resolution and Sharpness in Beam Based Methods with a Range from Nanometres to Micrometres”.
N. J. Everall, Analyst, 2010, 135, 2512.
N. J. Everall, Appl. Spectrosc., 2009, 63, 245A.
J. Park, J. Kim, and H. Kwon, Bull. Korean Chem. Soc., 2020, 41, 34.
Y. Kim, E. J. Lee, S. Roy, A. S. Sharbirin, L.-G. Ranz, T. Dieing, and J. Kim, Curr Appl. Phys., 2020, 20, 71.
National Metrology Institute of Japan (NMIJ), “Reference Material Certificate—NMIJ CRM 5207-a (Tungsten Dotarray)”, 2018, Tsukuba.
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Itoh, N., Hanari, N. Reliable Evaluation of the Lateral Resolution of a Confocal Raman Microscope by Using the Tungsten-dot Array Certified Reference Material. ANAL. SCI. 36, 1009–1013 (2020). https://doi.org/10.2116/analsci.20P046
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DOI: https://doi.org/10.2116/analsci.20P046