Axial scanning in lensless microscopy to achieve high resolution

Abstract

The optical system is designed here, to miniaturize the mechanical scanning and number of phase patterns illumination in lensless microscopy. The random phase mask is positioned in vertical column before the sample, which encoded the sample information and resulted into a final image at the sensor plane. To improve the signal to noise ratio and resolution of final image, the axial direction scanning of sample and sensor (SS) is performed while keeping them mutually immovable. This operation gathered the lost information of sample in between the sample and sensor planes. This axial motion of SS is performed with periodic steps, which would help in the reconstruction process during post processing. The final image has resolution of about 4 µm and field of view of 15 mm2. There are numerous advantages of such type of techniques, including portability and fast processing of data.