Single-shot in-line Fresnel incoherent holography using a dual-focus checkerboard lens

Abstract

Fresnel incoherent correlation holography (FINCH) is a technology that can acquire three-dimensional information of incoherent objects such as fluorescence with an in-line optical system. However, it is difficult to apply FINCH to dynamic phenomena, since FINCH has to detect phase-shifted holograms sequentially to eliminate twin and zero-order images. In this paper, a method in which the phase-shifted holograms can be obtained simultaneously with an in-line setup by using an optimized simulated diffraction optical element (sDOE), realized by a phase-only spatial light modulator, is proposed. The optimized sDOE is an optical device with a dual-focus lens, 2D grating, and spatial phase shifter. Therefore, the sDOE is called a dual-focus checkerboard lens. The optical experiment confirms the feasibility of the proposed method.

Roadmap on Recent Progress in FINCH Technology

“…To implement a snapshot of 3D images or record 3D movies, a single-shot technique is promising. Although many single-shot techniques have been proposed [13,34,[46][47][48][49][50][51], utilizing dual-phase gratings works with any image sensor in principle, which is useful for optimizing an optical setup with respect to cost, robustness to noise, frame rate, pixel pitch, quantization level, and the number of pixels. By improving light utilization efficiency and reducing the noise, FINCH would be a significant technology for the imaging and measurement community.…”

“…It realizes single-shot recording, but the spatial resolution of the hologram is reduced to about one-third. Another method using two diffraction optical elements (DOEs) has been proposed [34]. Although the spatial resolution of the method is half that of the FINCH with the time-division phase-shifting technique, four holograms are obtained simultaneously.…”

“…The optical setup for parallel phase-shifting single-shot in-line Fresnel incoherent correlation holography using a dual-focus checkerboard lens (DFCL) is shown in Figure 4. The details of the design method of DFCL are referred to [34]. The point is that a single DOE, which is a DFCL generates four phase-shifted holograms simultaneously.…”

“…You can see phase-shifted Fresnel zone patterns as holograms. [34]. Although the spatial resolution of the method is half that of the FINCH with the timedivision phase-shifting technique, four holograms are obtained simultaneously.…”

“…Nobukawa et al proposed a smart spatial multiplexing approach using a dual-focus checkerboard lens using the conventional Michelson interferometer-based configuration with two spatial light modulators (SLMs), one for each phase modulation, and achieved single-shot FINCH [33]. Later, in 2020, the research group led by Nomura demonstrated an advanced version of single-shot FINCH by spatial random multiplexing of the two different phase functions and with a single SLM and in a single-channel configuration [34]. In the same year, a geometric phase lens and 4-polarization camera were used to demonstrate single-shot FINCH [35].…”