Fresnel incoherent correlation holography (FINCH) is one of the methods for recording digital holograms of 3D samples
under incoherent illumination. This method has been successfully applied to white reflective holographic imaging and
3D microscopic imaging. In this article, the processes of optical recording, digital reconstruction and the point spread
function of the classic FINCH system are described in detail. The reconstruction images of three letters of “Z”, “W” and
“F”, each of which has a different distance from the collimating lens, are simulated. The expression of the resolution of
FINCH system has been deduced, which shows that the resolution of the optimal FINCH is beyond the Rayleigh
resolution. Effect of the background light on the resolution is analyzed through two groups of contrast experiments when
introducing the polarizer in FINCH system and changing phase masks on the SLM.
Fresnel incoherent correlation holography (FINCH) is one of the 3D imaging techniques which records holograms under incoherent illumination. A spatial light modulator (SLM) is used to split the incoherent light reflected/emitted from each object point into two self-coherent spherical beams with different curvatures, and the interference fringes is recorded by a CCD. This technology has been well used in white light reflection imaging and 3D fluorescence microscope imaging. We present a new idea of 4D imaging including three-dimensional spatial information and one-dimensional spectral information on the basis of FINCH. A mathematical model of 4D FINCH system using dual diffractive lenses on a spatial light modulator has been established. We obtained the specific forms of the point spread function, the axial magnification and the reconstruction distance. The experimental results of 3D FINCH imaging are given and one example of 4D imaging with three channels is numerically simulated. And we discussed the key problems of 4D imaging at last.