Sectional imaging of spatially refractive index distribution using coaxial rotation digital holographic microtomography

We propose and demonstrate a novel optical section imaging technique to measure the spatially refractive index (RI) distribution inside a sample using coaxial rotation digital holographic microtomography (DHμT). In this method, the illuminated laser source and image sensor are lined up and simultaneously rotated around the sample. The transmitted waves collected from the sample are used to generate a symmetric frequency, coverage as in a sample-rotation approach was discussed and simulated theoretically. We experimentally performed the sectional imaging of the RI inside a silicon micro-bead immersed in a liquid surrounding medium, to confirm the coaxial rotation DHμT as having the phase stability for tomographic recording and the reconstruction process. This sectional imaging technique is applied to measure the spatially RI distribution of a fusion structure between a single mode fiber and a polarization-maintaining fiber.