Gabor Fusion Master Slave Optical Coherence Tomography

Abstract

The communication refers to a solution to repetitive change of focus when performing swept source (tunable laser) interferometry. There are now swept source (SS) lasers exhibiting several meters coherence lengths for robotic navigation and cubic meter OCT. However, micron lateral resolution can only be achieved with sufficient high numerical aperture interface optics, in which case the depth range falls below sub-millimeter. Repetition of data collection is needed for each new focus (Gabor). This counteracts the advantage of SS-OCT, that of delivering information from all depths in one scan via a Fourier Transform (FT). To eliminate the time wasted on producing data from all axial range, Master Slave (MS) OCT is proposed, that delivers data while laterally scanning the beam, from a single depth of interest, in real time. We present combination of MS-OCT with 4 repetitions of acquisitions each for a different focus position, to acquire high resolution volumes and en-face OCT from different targets. By combining the two techniques, Gabor filtering and Master/Slave-OCT, a powerful imaging instrument is demonstrated. The MS technique allows simultaneous display of three categories of images in one frame: multiple depth en-face OCT images, two cross-sectional OCT images and a confocal like image obtained by averaging the en-face ones. We also demonstrate the superiority of MS-OCT over its FT based counterpart when used with a Gabor filtering OCT instrument in terms of the speed of assembling the fused volume.