Efficient Profilometry Using Tilted Grating Scanning Structured Illumination Microscopy

Abstract

Traditional structured illumination microscopy (SIM) base on phase-shift algorithm requires multiple images for each scanning location to calculate the modulation depth response (MDR), which results in low measurement efficiency. In this letter, we develop an efficient method called tilted grating scanning structure illumination microscope (TS-SIM) to enhance the measurement speed. In this method, we scan the tilted grating in a direction perpendicular to the optical axis to generate the intensity curve for each pixel. After that, the Fourier transform algorithm is applied to extract the MDR curve for each pixel from the corresponding intensity. The position with the maximum value of MDR for each pixel is extracted to reshape the surface topography precisely. With this technique, only one image is demanded for each scanning position which significantly improves the efficiency, demonstrating the potential to be applied in fast measurement. The experiment and theoretical analysis are elaborated to verify the feasibility of the method.