Dynamic-range-extended line-field interferometric profiling with high-speed in-fiber optical delay control

A high-speed dynamic-range-extended white light interferometry (HS-DRE-WLI) system is developed for fast, high-resolution 3D surface profiling across varying reflectance levels. The system combines high-speed fiber-stretcher-based optical path difference modulation with an asymmetric line-illumination technique to enhance imaging speed and dynamic range. Chromatic and polarization-induced distortions are minimized through dispersion compensation using optimized fiber lengths and a Faraday rotator, achieving 14.2-μm axial resolution. Validated on diverse samples, the system captures fine and large-scale features with high fidelity, demonstrating strong potential for industrial and biomedical applications requiring accurate, robust surface measurements.