High-speed optical comb-based 3D tomographic profiling using Fourier-transform method with reduced-frame acquisition

We propose a high-speed full-field tomographic imaging method based on Fourier fringe analysis (FFA) integrated with broadband multi-GHz electro-optic comb interferometry. The proposed approach eliminates measurement null points while simultaneously reconstructing amplitude and phase distributions from interference peak envelopes that are free of temporal carrier fringes along the depth-sweep direction, while transverse spatial carrier fringes are used for FFA. By avoiding temporal phase modulation, the approach achieves substantially higher imaging speeds with only a limited number of frames, enabling millimeter-scale volumes to be reconstructed within several tens of milliseconds. This reduced-frame acquisition strategy allows volumetric imaging at speeds previously unattainable with conventional methods. Measurements of step-height standards, nanostructured IC wafers, glass plates, and dynamically vibrating glass plates demonstrate absolute depth-resolved imaging, dynamic tomographic measurement, and nanometer-scale surface profiling capabilities.