Quantitative phase imaging by common-path interferometric microscopy: Application to super-resolved imaging and nanophotonics

Quantitative phase imaging needs of a holographic setup in order to retrieve the sample phase distribution. Often this new phase information is obtained at the cost of reducing the useful range in other parameters of the imaging system such as field of view or resolution. We devised an experimental setup that allows complex amplitude evaluation and phase image quantification of three-dimensional (3-D) samples in wide-field digital holographic microscopy. The basis is a common-path interferometric configuration that can be implemented in two configurations depending on the position and the basic period of the grating: static grating and windowed Fourier filtering method or with phase-shifting moving grating. Both configurations allow complex amplitude recovery and, thus, quantitative phase imaging of the sample under test. Moreover, by combining the basic setup with tilted illumination and time multiplexing, it is possible to generate a synthetic aperture enlargement that improves the final image resolution. Experimental results validated our concepts.