Replacing the Fourier transformation in optical coherence tomography with multiple comparison operations

The conventional spectral domain (SD) and Fourier domain (FD) OCT method deliver a 1D reflectivity profile in the sample investigated by applying a Fourier transform (FT) to the channeled spectrum, CS, at the interferometer output. We discuss here the advantages of a novel OCT technology, Master Slave (MS). The MS method radically changes the main building blocks of a SD (FD)-OCT set-up. The serially provided electrical signal in conventional technology is replaced by multiple signals, a signal for each OPD point along an electrical output for each depth in the object investigated. In this way, it is possible to: (1) direct access to information from selected depths; (ii) eliminate the process of resampling, required by the FT based conventional technology, with immediate consequences in improving the decay of sensitivity with depth, achieving the expected axial resolution limit, reduction in the time to display an image and lower cost OCT assembly; (iii) OCT interferometer tolerant to dispersion left unbalanced.