Grating-based in-line geometric-phase-shifting incoherent digital holographic system toward 3D videography.

Incoherent digital holography (IDH) with a sequential phase-shifting method enables high-definition 3D imaging under incoherent lights. However, sequential recording of multiple holograms renders IDH impractical for 3D videography. In this study, we propose grating-based in-line geometric-phase-shifting IDH.

Transformation of coherence-dependent bokeh for incoherent digital holography.

Incoherent digital holography (IDH) enables the recording of holograms with incoherent light. However, there is unnatural bokeh with ringing on reconstructed 2D images, owing to the diffraction calculation based on the coherent nature of the light. Thus, we propose a transformation method that converts it into incoherent bokeh.

Highly efficient dual page reproduction in holographic data storage.

We propose a simultaneous dual-page reproduction for holographic data storage (HDS) with high-efficiency and high-speed data reproduction by reusing a transmitted reference beam that passes through a recording medium after data reconstruction. The transmitted reference beam enters the recording medium at a different incident angle to reproduce different data pages; thus, this technology can double data-transfer rates without increasing the laser's output power or preparing another laser source. In the experiment, neighboring angle-multiplexed two data pages were simultaneously reconstructed and a data transfer rate of 1.

Coherence aperture restricted spatial resolution for an arbitrary depth plane in incoherent digital holography.

Incoherent digital holography (IDH) requires no spatial coherence; however, it requires high temporal coherence for a light source to capture holograms with high spatial resolution. Temporal coherence is often enhanced with a bandpass filter, reducing the light utilization efficiency. Thus, there is a trade-off between spatial resolution and light utilization efficiency.

Incoherent digital holography simulation based on scalar diffraction theory.

Incoherent digital holography (IDH) enables passive 3D imaging through the self-interference of incoherent light. IDH imaging properties are dictated by the numerical aperture and optical layout in a complex manner [Opt. Express27, 33634 (2019)OPEXFF1094-408710.

Sampling requirements and adaptive spatial averaging for incoherent digital holography.

Incoherent digital holography (IDH) enables passive 3D imaging under spatially incoherent light; however, the reconstructed images are seriously affected by detector noise. Herein, we derive theoretical sampling requirements for IDH to reduce this noise via simple postprocessing based on spatial averaging. The derived theory provides a significant insight that the sampling requirements vary depending on the recording geometry.

Bimodal Incoherent Digital Holography for Both Three-Dimensional Imaging and Quasi-Infinite-Depth-of-Field Imaging.

Although three-dimensional (3D) imaging and extended depth-of-field (DOF) imaging are completely opposite techniques, both provide much more information about 3D scenes and objects than does traditional two-dimensional imaging. Therefore, these imaging techniques strongly influence a wide variety of applications, such as broadcasting, entertainment, metrology, security and biology. In the present work, we derive a generalised theory involving incoherent digital holography to describe both 3D imaging and quasi-infinite-DOF (QIDOF) imaging, which allows us to comprehensively discuss the functions of each imaging technique.

Single-shot phase-shifting incoherent digital holography with multiplexed checkerboard phase gratings.

Single-shot phase-shifting incoherent digital holography with multiplexed checkerboard phase gratings is proposed for acquiring holograms of moving objects. The gratings presented here play the following three roles: dividing the beams, modulating the curvature of spherical beams, and introducing different phase shifts. With the gratings of our proposed method, four individual holograms of a spatially incoherent light are formed on an image sensor.

Dual-page reproduction to increase the data transfer rate in holographic memory.

To increase the reproduced data transfer rate in holographic memory, we have investigated simultaneous reproduction of two data pages. By irradiating s- and p-polarization reference beams whose angle gap is equal to the angle between the neighboring data pages in angle-multiplexed holograms, two different data pages can simultaneously be reproduced with a bit error rate low enough to decode. This technology is effective to double the data transfer rate in holographic memory.