2D parallel optical coherence tomography and multiple-layer information extraction

During the past decade, optical coherence tomography (OCT) has been vigorously developed into a powerful tool for biomedical diagnosis applications. Because this technology has the nature of extracting the internal features of an object, its applications can be extended to document security, biometrics identification, and industrial inspection. In addition, its high imaging resolution makes OCT an ideal tool for massive storage/retrieval of 3D data. In this paper, we propose the 2D parallel OCT system and its application for multiple-layer information retrieval. We will study the issues that exist exclusively in this type of application, such as interlayer phase/intensity modulation and the parasitic fringe patterns resulting from the surfaces of the information layer. The basic procedure of the proposed OCT system includes three steps: 1) extraction of cross-section raw images at each layer of an object; 2) removal of the interfering fringes by algorithm derived from multiple phase-shifted images; 3) elimination of interlayer modulations and parasitic patterns. Other issues that may degrade the retrieved images are also discussed. The simulation results and experimental tomography obtained from different testing samples are presented and discussed.