real-time acquisition of an image of an optical fiber to be processed on a three-dimensional translation stage; the three-dimensional translation stage being parallel to an X axis and a Y axis, and perpendicular to a Z axis, the X-axis, the Y-axis and the Z-axis forming a three-dimensional coordinates system, wherein the optical fiber includes a fiber core and cladding and is to be processed using a laser with a laser focus at an XY coordinate;

adjusting a relative position of the optical fiber and a microscope objective in a direction along the Z-axis until two boundary lines between the fiber core and the cladding are identified in the acquired image;

calculating the position of the center point between the two boundary lines on the three-dimensional translation stage to determine an XY coordinate of the position of the center point;

according to the position of the center point, adjusting the position of the optical fiber on the three-dimensional translation stage until the XY coordinate of the center point coincides with the XY coordinate of the laser focus.