Vibration-robust lateral-scanning white-light interferometry via spatially coupled optical phase estimation

Lateral scanning white-light interferometry (LSWLI) is a non-contact technique for three-dimensional surface measurement. However, high-speed scanning errors and off-axis vibrations degrade coherence-peak localization and reconstruction accuracy. In this Letter, we present a spatially coupled optical phase estimation network (SCOPE-Net) to jointly estimate lateral displacement and vibration-induced phase perturbation from sequential interferograms. The estimated displacement is used for spatial-sampling correction, while the estimated phase is used for phase-shift correction, enabling robust reconstruction of disturbed interferometric signals. Simulations and experiments demonstrate that the proposed approach achieves subpixel-level displacement and phase-perturbation estimation and maintains height-measurement accuracy comparable to conventional white-light interferometry (WLI) at a scanning speed of approximately 1 mm/s, even under off-axis perturbations.