Phys.org  May 19, 2020 In biological microscopy and X-ray imaging, many transparent objects or structures are difficult to observe due to their low absorption of light. Researchers in China have demonstrated that adjusting the polarizers can optically compute the spatial differentiation of the incident light field along different directions. They improved contrast by tuning a uniform constant background as a bias, creating a virtual light source that casts a shadow on the measured images. Based on this bias approach, they can distinguish the phase increases and decreases in light field distribution and quantify the optical thickness of observed objects with […]