Master-Slave optical coherence tomography for parallel processing, calibration free and dispersion tolerance operation

Abstract

ABSTRACT We present further improvements on the Master Slave (MS) interferometry method since our rst communication[1]. In this paper, we present more data collection and additionally demonstrate an important feature of theMS method, that of tolerance to dispersion. MS interferometry produces the interference of a selected pointin depth based on principles of spectral domain (SD) interferometry, but without the need of a Fast Fouriertransformation (FFT). The method can be used to directly produce en-face optical coherence tomography(OCT) images but also as a tool to accurately measure distances in low coherence interferometry for sensingapplications [1]. In the MS-OCT method, cross-correlation is applied to both methods of SD-OCT, spectrometerbased (SP) or swept source (SS) OCT. The channelled spectrum provided by an OCT system is correlated withthe signal produced by reading a stored mask. Several such masks can be used simultaneously. The masksoperate as adaptive lters. Each mask ( lter) determines recognition in the measured channelled spectrumdelivered by the interferometer, of the pattern corresponding to each optical path di erence to be recognized.The method presents net advantages in comparison with the classical method of producing axial reectivitypro les by FFT: no need for resampling of data, possibility to tailor the trade-o between depth resolution andsensitivity. Here, using a swept source, the MS method is used to obtain axial reectivity pro les, which arecompared to the axial pro les obtained by calibration of data and FFT. The tolerance to dispersion of the MSmethod was assumed in [1] but not demonstrated. Here, measurements are performed to demonstrate its axialresolution independence on dispersion.Keywords: master slave, optical coherence tomography, CUDA, GPU, parallel computing, en-face imaging