AUTOMATIC SURFACE SHAPE MEASUREMENT APPARATUS AND METHOD USING LASER INTERFEROMETRY

摘要

An automatic surface shape measurement apparatus and method using laser interferometry. The apparatus comprises: a laser interferometer (4), a binocular camera (1), a diffraction light spot receiving camera (3), a CGH, a light spot receiving screen having a central light passing hole, a lens under test, and a projection crosshair detector (2); the laser interferometer (4) is fixedly connected to the binocular camera (1); the diffraction light spot receiving camera (3) is fixedly connected to the CGH; the lens under test is fixedly connected to the projection crosshair detector (2); the CGH is placed in front of the focus of a standard lens of the laser interferometer (4) in a direction away from the laser interferometer (4); the light spot receiving screen having a central light passing hole can be removed and put back at the focus of the standard lens of the laser interferometer (4). According to an automatic multi-stage pose adjustment method for a laser interferometry surface shape measurement light path based on the binocular camera (1), the projection crosshair detector (2), the diffraction light spot receiving camera (3), and interference fringe aberration decoupling, a jump from mm-level mechanical positioning to sub-micron level optical positioning is achieved, and thus, automatic nm-level optical element surface shape measurement is completed.