3D nano surface profilometry by combining the photonic nanojet with interferometry

19th International School on Condensed Matter Physics: Advances in Nanostructured Condensed Matter: Research and Innovations

Montgomery, P.C.^1 ; Lecler, S.^1 ; Leong-Hoï, A.^1 ; Pfeiffer, P.^1

Laboratoire des Sciences de l'Ingénieur, de l'Informatique et de l'Imagerie (ICube), Unistra-CNRS, UMR 7357, 23 rue du Loess, Strasbourg Cedex

67037, France^1

关键词: Axial resolutions;    Biological science;    Far-field imaging;    High-lateral resolution;    Interference microscopy;    Lateral resolution;    Microscopic surface;    Resolution limits;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/794/1/012006/pdf
DOI  :  10.1088/1742-6596/794/1/012006

来源: IOP

【 摘 要 】

Interference microscopy has become a standard technique for measuring microscopic surface roughness, being rapid, non-contact and having a high nanometric axial resolution. Nonetheless, a limitation is the lateral resolution of λ/2 due to diffraction. Amongst the many recently developed techniques for improving the lateral resolution in unlabelled far field imaging, the use of microspheres placed on the sample has recently been extended from 2D imaging to 3D measurement by combining it with interferometry. In the present work, results are shown of combining the high lateral resolution of the photonic nanojet produced by the microsphere with interference microscopy to achieve sub-diffraction limited lateral resolution with nanometric axial resolution. This is achieved by imaging through a microsphere placed on top of the sample in front of the interference objective in a Linnik setup. Results of the 3D measurements of narrow gratings through the microsphere are presented, that are not observable with the same objective in air since they are below the resolution limit. Simulations of the interaction between the photonic jet and the grating leads to a basic understanding of the image formation. This new technique opens new possibilities for high resolution characterization in nanomaterials and the biological sciences.