Portable digital holographic microscope using spherical reference beam

In this study, we developed and evaluated a portable digital holographic microscope (DHM) using a spherical reference beam. To reduce the size of this DHM, we replaced the objective lens with a small aspherical single lens, which produces the spherical reference beam. In addition, integrating the CCD camera and beam splitter yielded a simplified alignment along with further microscope compactness, resulting in a DHM with dimensions of 150 (W) × 470 (D) × 244.5 (H) mm 3 , which is a portable size. The spatial resolution of the developed DHM was evaluated and a value of 870 nm was experimentally obtained, similar to the theoretical resolution of 851 nm. In addition, we conducted measurements on leukemia cells to evaluate the applicability of our novel microscope to cystoscopy.