Full-Field Swept Source Master-Slave Optical Coherence Tomography

We apply the principle of master-slave (MS) interferometry to a full-field swept source optical coherence tomography (OCT) setup equipped with a fast 2-D camera. MS interferometry does not involve Fourier transformations and, therefore, eliminates the need for spectrum data resampling required by the conventional spectral domain OCT. Using this method in a full-field OCT setup, en face images are acquired in vivo from finger skin, Drosophila melanogaster larvae, and pupae, with no spectrum resampling and no mechanical scanning. The signal processing is based on a comparison operation of the shapes of channeled spectra for each camera pixel, with a set of reference signals (masks). In this way, en face OCT images can be obtained with no need for the volumetric assembly and software cutting the en face images from an image volume, which are required by the conventional spectral domain OCT method. We demonstrate that the sensitivity and axial resolution of the MS method in a full-field swept source OCT setup are similar to the values obtained using the conventional Fourier-transformation-based swept source OCT method in a full-field setup. Multiple en face images can be produced in parallel by using multiple stored shapes of channeled spectra for the depths of interest. The full-field MS-OCT method presented here opens the possibility of parallel processing for all image points in a 3-D volume of the object.