Abstract

Ptychographic imaging is centered on the phase retrieval of the sample from the diffraction patterns recorded at the sensor. Ptychography is a lens less computational imaging method that has various types. The single aperture ptychographic imaging technique is discussed in this design. Firstly, the simulation is done by MATLAB and after that the physical experiment is performed. The amplitude and phase-reconstructed images are retrieved by pinhole illumination. The sample is illuminated through the pinhole (generated by SLM) and the encoded sample information propagates to the CMOS, which is positioned at an optimum distance and captures the images. The Ten different diffraction patterns of the specimen are recorded by the CMOS sensor by shifting it axially and the data is recorded on the computer. To retrieve the phase and amplitude information about sample from raw images the reconstruction process is applied through MATLAB. The recorded field is back propagated to the object plane in the reconstruction process. Finally, by including all the back propagated images, a final reconstructed image with higher resolution is obtained using the stochastic gradient descent technique. The noise suppression approach is added to the final image to further increase resolution. The final image is highly resolved. Lens-less microscopy generates a cost-effective, portable optical device. Ptychography have many applications in medical field. It is used within the human body to detect biological cells. This provides good results in diagnosis of diseases.

© 2021 The Author(s)