TRANSIENT DIGITAL MOIRE PHASE-SHIFT INTERFERENCE MEASUREMENT DEVICE AND METHOD FOR SURFACE FIGURE OF OPTICAL ELEMENT

摘要

A transient digital Moire phase-shift interference measurement device and method for the surface figure of an optical element. The transient digital Moire phase-shift interference measurement device and method for the surface figure of the optical element overcome a defect that the instantaneous vibration resistance needs to be exchanged for a measurement range when a two-step carrier splicing method is used, expand the measurement range of a conventional digital Moire phase-shift method, and also retain the instantaneous vibration resistance of the digital Moire phase-shift method. The device comprises: a light source (1), a spectroscope (2), a reference mirror (3), a first polarization grating (4), a measured mirror (5), a second polarization grating (6), a first imaging objective lens (7), a first camera (8), a second imaging objective lens (9), and a second camera (10). Different carriers are loaded by means of the light splitting performance of the polarization gratings, the two beams of interference light are separated by means of the polarization gratings, and two actual interference patterns are obtained at the same time.