Dispersion Correction for Optical Coherence Tomography by Parameter Estimation in Fractional Fourier Domain

The fractional Fourier transform (FRFT) illustrates the physics behind chromatic dispersion in Fourier domain Optical Coherence Tomography(FD OCT). However, it fails in compensating the depth-dependent dispersion with high accuracy and speed which is required in some areas, especially in medical diagnosis. This paper presents a new fractional Fourier domain(FRFD) dispersion compensation approach based on Quasi-Newton optimization. The method consists of two searching steps, achieving in a computation reduction with high accuracy guaranteed. As for depth-dependent dispersion, a component-separating method is proposed in order to extract the weak dispersion under the interference of the stronger ones. The performance of the estimate errors is analyzed and compared with the traditional FRFT filtering method in computing simulations. Finally, we present a practical application in compensating the dispersion in Intravascular Optical Coherence Tomography(IVOCT), resolving the obfuscation problems in segmenting the lumen boundaries.