Diffraction phase microscopy (DPM) provides the possibility of high-resolution quantitative phase imaging, based on equipment of an optical microscope with a special module working in a common-path off-axis configuration. As an optical microscopy technique, DPM has a limited focus depth, which is the smaller the higher is the objective's numerical aperture. In this paper we present the results of experimental investigation of numerical focusing with the angular spectrum method in DPM.
Nowadays is developed a lot of techniques for the refractive index measurements. One of them describe in this article. We are used method of optical microscopy, there is diffraction phase microscopy with transmissionreflection illumination for measurements of red blood cells (RBCs) refractive index. Theory of measurements refractive index and results of experiments also are presented in the article.
Fourier optics approach is employed in the work do describe formal theory of diffraction phase microscope (DPM). Final expression for optical field in registration plain is given. Optimal spatial filter diameter and numerical aperture is calculated theoretically. DPM is used in the work for reconstruction of phase map of red blood cells in blood slide. The filter windows diameter influence on phase map reconstruction is shown experimentally.
Experimental setup of diffraction phase microscope (DPM) with double low-coherence lighting system is presented in the paper. Algorithm of interference picture processing and optical thickness, height, volume and mean cells volume (MCV) of RBC calculating is shown. We demonstrate results of experiments with blood smears and ability of the method to calculate 3D model of the biological cells shape. Investigation change dynamics of RBC morphology after injection glucose for diabetes by DPM is shown in the paper.