Common path swept-source OCT interferometer with artifact removal

Abstract

We present here the implementation of a fiber-based common-path interferometer for Swept Source Optical Coherence Tomography (SS-OCT). A common path configuration is often a suitable approach for increasing the stability of the measurements. Optical fibers are sensitive to temperature and some other mechanical perturbations which compromise absolute accuracy measurements. A common-path configuration provides a mean to define a reference at the probe location and, thereby, to compensate for the optical path length perturbations. Additionally, in SS-OCT, we have to deal with autocorrelation noise and the mirror image artifact due to the computation of the Fourier transform. Thus, our common-path implementation also includes acousto-optics modulators to remove the depth degeneracy as it has already been done when using a traditional interferometer configuration. The efficiency of our system is validated by comparing images acquired with a traditional SS-OCT configuration and with our common path SS-OCT configuration.