Optical sectioning using a digital Fresnel incoherent-holography-based confocal imaging system

Abstract

We propose a new type of confocal microscope using Fresnel incoherent correlation holography (FINCH). Presented here is a confocal configuration of FINCH using a phase pinhole and point illumination that is able to suppress out-of-focus information from the recorded hologram and hence combine the super-resolution capabilities of FINCH with the sectioning capabilities of confocal microscopy.

Improved axial resolution of FINCH fluorescence microscopy when combined with spinning disk confocal microscopy

“…Complex deconvolution methods may provide similar benefits. A proposed SLM-based confocal FINCH [18,19] has recently appeared.…”

CINCH (confocal incoherent correlation holography) super resolution fluorescence microscopy based upon FINCH (Fresnel incoherent correlation holography)

“…Widefield and confocal images as well as FINCH and CINCH holograms were recorded by the cameras. It should be noted that our CINCH holographic confocal configuration differs from a recently proposed SLM based holographic confocal FINCH 20 , since our method (i) utilizes all-transmission geometry and multiplexed analog pinholes rather than reflective SLMs and digital phase pinholes to obtain confocal FINCH images, and (ii) enables a ready comparison with either widefield or confocal images on the exact same field.…”

Incoherent digital holography with phase-only spatial light modulators

“…Last year, a motionless, SLM-aided, confocal setup of FINCH was presented 44 as a new sectioning method and as an answer to the problem of the relatively low axial resolution of conventional FINCH. 51 Several months after the appearance of the first confocal FINCH, 44 another confocal microscope was proposed, combining standard FINCH with a spinning disk.…”

“…51 Several months after the appearance of the first confocal FINCH, 44 another confocal microscope was proposed, combining standard FINCH with a spinning disk. 52 However, note that the original confocal FINCH 44 is motionless and accomplishes optical sectioning of the observed specimen without losing the inherent transverse super-resolution capabilities of the original FINCH. 21 Therefore, confocal FINCH can image different planes of interest at various depths while blocking light from other planes.…”

“…Fortunately, scanning of the entire object can be performed without any mechanical movements by electronically shifting the phase pinhole onto different pixels of SLM 2 . 44 In the sectioning experiments, results of a conventional FINCH (Fig. 3) were compared to an optical sectioning FINCH (as shown in Fig.…”