Super-Resolution of Optical Thickness Measurement employing Correlation-based Spectrum Estimation

The quantification of optical thickness using a wavelength swept source is pivotal for applications such as Swept Source Optical Coherence Tomography (SS-OCT) and Frequency-Modulated Continuous-Wave (FMCW) lidar, demanding sub-millimeter range resolution. To enhance resolution, we advocate the incorporation of a correlation-based spectrum estimation method in FMCW optical thickness measurement. Our approach successfully resolved a notable 0.59 mm of thickness with a 1.7 nm wavelength sweep, surpassing the 0.61 mm theoretical limit imposed by Fourier transform.