HIGH RESOLUTION IMAGING OF BIO-TISSUES

Optical Coherence Tomography is a technology capable of generating high resolution micron-scale cross-sectional images of complex structures in real time. It relies on low coherence interferometry utilizing spectrally broad light sources. There are many types of OCT systems such as the Time Domain Frequency Domain Swept Source Doppler and Polarization Sensitive system; of these the Fourier Domain OCT system has got comparably higher resolution and sensitivity. The typical OCT setup is a Michelson Interferometer. The OCT setup was initiated in the laboratory at SAMEER using an SLD of spectral width 20nm. In the first phase the thickness of polythene sheet was measured from the fringe width difference introduced due to the sheet. The measured thickness is 4.6 µm. In the second phase the Michelson Interferometer was set up for Fourier Domain OCT. Different samples were studied and spectrograms of the samples were recorded and analyzed. The spectrograms were signal-processed using MATLAB to generate two-dimensional cross-section images of the samples. An axial resolution of 3µm is obtained for the images from the current setup.