For decades, imaging weakly scattering phase objects such as cells has been an active area of research across various fields, including biomedical sciences. One common approach uses chemical stains or fluorescent tags to bring image contrast to weakly scattering objects, but it requires relatively complex sample preparation steps, which can also be toxic or destructive to samples. Quantitative phase imaging (QPI) has emerged as a powerful label-free solution to this need, providing non-invasive, high-resolution imaging of transparent specimens without using any external tags or reagents.
