Fresnel incoherent digital holography with large field-of-view

Abstract

Incoherent digital holography (IDH) is a recently proposed technique to record three-dimensional (3D) information about the object under incoherent illumination, which breaks the limitation that the holographic recording must be illuminated by coherent light sources and thus makes it usable in white-light and fluorescence illuminating circumstance. In particular, the fresnel incoherent correlation holography (FINCH) is an exemplary method which improves the imaging resolution power and efficiency of incoherent digital holography, and it can obtain 3D distribution of objects swiftly without scanning and moving. However, compared with the conventional optical holography, the FINCH system has a very small field-of-view due to the limitation of the pixel number and size of spatial light modulator (SLM). Therefore, expanding the recording field-of-view of FINCH system is very significant for the application of IDH. In the FINCH, the SLM is used as a diffractive beam splitter so that each spherical beam, originating from each object point, is split into two spherical beams with two different curve radii. Then the interference fringes between the two beams are recorded by CCD. In this paper, the field-of-view angle recorded by the SLM is proposed and analyzed based on the physical and numerical principles of the FINCH system. The field-of-view of imaging system is improved by increasing the effective diameter of SLM through moving the center of the dual-lens optical axis mounted on the SLM to the edge in different directions respectively. An optical setup of reflection mode is constructed to verify the theoretical analysis of this study, and the sub-holograms in different field-of-views are obtained by CCD through changing the masks displayed on the SLM sequentially. Then, the complex holograms in different field-of-views are obtained by using the three-step phase-shifting method, and the reconstructed images are acquired respectively through the angular spectrum method (ASM) by using a computer. Finally, the large field-of-view image is obtained by stitching the reconstructed images in each field-of-view by utilizing the matlab program. The experimental results show that the efficient recording field-of-view of SLM can be increased by 2.77 times with our proposed method. Accordingly, the recording field-of-view of the system is improved significantly. The recording field-of-view of the FINCH system will increase further if the center of the dual-lens optical axis continues to move toward the edge. Therefore, this study provides an important support for the further application of high resolution microscopic imaging with large field-of-view.

Impact of the spatial coherence on self-interference digital holography*

“…Among various schemes, a kind of techniques referred to as the self-interference digital holography (SIDH) [5][6][7] is particularly attractive and has been used in various applications, such as color holography, [8] fluorescence microscopy, [9] 3D imaging, [10] super-resolution, [11,12] adaptive optics, [13,14] imaging through random media, [15,16] and others. [17][18][19][20] The optical trick of SIDH is that, with the aid of suitable optical components, the incident wave originated from an object point is split into two parts, and then they can be recombined together in a recording plane and interfere with each other to form a hologram. Even though extensive works on SIDH have been carried out, some essential issues of SIDH remain to be clarified.…”

Two-step phase-shifting Fresnel incoherent correlation holography based on discrete wavelet transform*

“…[6,7] Therefore, the incoherent digital holography technology has been increasingly developed. [8][9][10][11][12] Fresnel incoherent correlation holography (FINCH) originally proposed by Rosen and Brooker [13,14] has developed rapidly and extensively in the field of imaging. [15][16][17][18][19][20] The FINCH presents a factor of about 1.5 in resolution higher than a regular incoherent imaging system with the same NA, but the unwanted direct current (dc) term and twin image are superimposed on the reconstructed image.…”