Estimation and compensation of dispersion for high-resolution optical coherence tomography system

Balanced reference-sample arm dispersion is critical in optical coherence tomography systems in order to attain images with the highest axial resolution. Here, an experimental method for the estimation and correction of dispersion in an optical coherence tomography system is presented. The system dispersion was computed from two optical coherence tomography images of the reference mirror that were symmetrically placed around the zero delay point. The method was tested using a broad bandwidth spectral domain optical coherence tomography system, compensating for the dispersion caused by a 3-mm-thick fused silica flat placed in the sample arm. Using our method, dispersion compensation was achieved and the axial resolution was improved from 10.6 µm to 1.9 µm in air. Results suggest that this technique can be a simple and effective technique for eliminating axial resolution degradation due to dispersion mismatch between the sample and reference arm in high-resolution optical coherence tomography systems.