Single camera shot Fresnel incoherent correlation holography

Abstract

Fresnel incoherent correlation holography (FINCH) is a super-resolution incoherent imaging technique built on the principle of self-interference. In FINCH, the object wave is split into two, modulated by diffractive lenses with different focal distances and interfered to generate the hologram. At least three holograms with different phase-shifts between the two object waves were recorded and combined to synthesize a complex hologram. The different planes of the object were reconstructed by numerically propagating the complex hologram to one of the focal planes of the diffractive lenses. FINCH, in general, has a higher lateral resolution but lower axial and temporal resolutions than direct imaging. A new approach inspired by guide-star holography techniques is applied to FINCH. In this study, two diffractive lens functions with different focal lengths have been spatially multiplexed into one using a binary quasi-random function and fabricated using electron beam lithography. In the first step, the point spread hologram library was recorded by axially scanning a point object along the optical axis. In the next step, an object hologram was recorded. The three-dimensional image of the object was reconstructed using a cross-correlation between the point spread hologram library and the object hologram. The modified approach increased the time resolution of FINCH by three times, improved the axial resolving power and enabled the development of the most compact version of FINCH. We believe that FINCH can be applied for monitoring bacterial cell shape during contact with mechanically biocidal nanotextured surface and light matter interactions.