Modulated deconvolution for resolution improvement in Fourier Domain Optical Coherence Tomography

摘要

This manuscript presents a novel technique for axial resolution improvement in Fourier Domain Optical Coherence Tomography (FDOCT). The technique is based on the modulated deconvolution of OCT signals which results in a resolution improvement by a factor of ~ 7 without the need for a broader bandwidth light source. This method relies on a combination of two basic properties: beating, which appears when adding two signals of slightly different frequencies, and the resolution improvement, achieved by deconvolution of an OCT image with the encoded source autocorrelation function. In FDOCT the real part of the FFT of the interferogram is modulated by a frequency which depends on the shift in position of the interferogram. A slightly shifted interferogram will, therefore, result in an A-Scan which will have a different modulation frequency. Beating will appear when two such A-Scans, with an appropriately selected amount of shift, are added. Deconvolution of the resulting signal, using suitable kernels, results in a narrower resolution width.