Endoscopic common-path OCT based on sweeping laser source and curled optical patch cord

Abstract

Several technical problems have to be overcome before Optical Coherence Tomography (OCT) can be accepted among the established endoscopic imaging modalities. Most of conventional Michelson-based OCT systems need to have two separated paths of the sample and reference arms, which limits the flexibility of endoscopic probe. Recently, common-path interferometer based OCT have been demonstrated to circumvent the mismatch problems of length, polarization, and dispersion between the reference and sample arms, but the interferometric scanning methods have been realized with time-domain PZT or spectral-domain CCD. In this work, we demonstrate a novel Fourier-domain common-path OCT based on sweeping laser source, which shows superiority in the speed and robustness. Using a holey optical fiber with low bending loss, a novel curled optical patch cord, like a curl cord of telephone, is also adapted for the convenient access to the biological target at the flexible distance. The freedom to use an arbitrary length and wiring of the probe can provide more flexibility for use in endoscopic OCT.