Towards an on-chip signal processing solution for the online calibration of SS-OCT systems

This paper demonstrates a low complexity, computationally efficient method for the real-time calibration of Swept Source Optical Coherence Tomography (SS-OCT) systems. In this work, Interpolated Discrete Fourier Transform (IpDFT) based algorithms were explored as a highly efficient alternative for instantaneous frequency measurement and wavenumber calibration of fast optical swept sources. Various IpDFT based methods are implemented and results are evaluated against commonly performed calibration techniques such as Hilbert transformation. Simulation shows execution times decisively improved by up to a factor of ten, depending on observational window length. Axial resolution was also slightly improved. Moreover, the inverse tangent and phase unwrapping steps necessary for Hilbert transform calibration techniques are eliminated, vastly reducing circuit implementation complexity and making the system suitable for future inexpensive, power efficient, on-chip solutions in SS-OCT post-processing.