The reconstructed image of a moving sample always shows a distorted representation of reality. Therefore, one needs to calibrate, for example, out-of-plane nano-videos for quality control of nano-microelectromechanical systems (N-MEMS). Here we discuss how to calibrate and obtain confidence limits for stroboscopic scanning white light interferometry (SSWLI) data when there are differences in speed and amplitude across the field of view. Many N-MEMS devices rely on oscillating structures; consequently, one must calibrate movie recordings of these structures to have global standards and to allow inter-device comparison. We propose to use a quartz tuning fork driven off-resonance as a transfer standard. This approach allows a broad range of traceable frequencies and out-of-plane amplitudes to be introduced into selected parts of the field of view of the SSWLI device featuring similar optical surface properties to many N-MEMS devices without demanding an additional reference surface.
Kassamakov, I., Tureanu, A., Heikkinen, V., & Hæggström, E. (2017). Transfer standard for traceable dynamic calibration of stroboscopic scanning white light interferometer. Applied Optics, 56(9), 2483-2488. https://doi.org/10.1364/AO.56.002483