Vibration-resistant white-light interferometry using auxiliary compound cavity with an extended source

This study presents a general vibration-resistant white-light interferometry (VWLI) for high-precision topography measurements in complex vibration environments. It employs an extended laser source in the laser interference channel to avoid reference mirror obscuration in the Mirau objective and uses an auxiliary compound interferometric cavity to establish a spatial phase-shifting interference path for instantaneous vibration detection, thereby achieving topography reconstruction in combination with the white-light interference channel. To validate the performance of the proposed method, comparative experiments were conducted in an environment with a vibration frequency ranging from 0 to 50 Hz and an amplitude of approximately 0.5 μm, yielding measurement deviations of less than 0.02% for the height and 0.74 nm for the roughness, respectively.