Design and Characterization of Precise Laser-Based Autofocusing Microscope with Reduced Geometrical Fluctuations

摘要

The present study proposes a laser-based microscope system in which a precise autofocusing capability is achieved using a position feedback signal based on the distance L between the geometrical center (X_c, Y_c) of the image captured by the CCD sensor and the centroid (xcentroid, ycentroid) of the image. The experimental results show that the proposed system has a positioning accuracy of 2.2 μm given a working range of ±200 μm. The autofocusing performance of the proposed system is thus better than that of a conventional centroid-based system, which typically achieves a positioning accuracy of around 5.2 μm.