This PDF file contains the front matter associated with SPIE Proceedings Volume 12025, including the Title Page, Copyright information, Table of Contents and Conference Committee list.

A first step toward all-optical network was successfully taken with graded-index perfluorinated polymer optical fibers (Gi-POF) spliced with glass optical fibers (GOF). The concept was demonstrated with optical fibers and with specially designed transceivers. In addition, the casings for transceiver devices involved were made of specialty magnesium alloy, which was demonstrated to be several times better than most other commonly used materials in shielding electrical contents from electromagnetic interference (EMI), a must-have feature for modern ultra-high-speed networks. We continue to work toward truly all optical networks by replacing O/E conversions even further with more optical/optical (O/O) connections..

We have developed 8K-ultra high definition (UHD) endoscopic system and 8K-UHD microscope system to reduce the burden on surgeons and contribute to improving medical safety. On the other hand 8K-UHD video has large data size than the conventional one such as HD and 4K-UHD videos, and it is difficult to secure sufficient recording time. Moreover these systems are expected to be used only in operating rooms, and extra technical supports and special player devices are required for presentation of 8K-UHD surgical movies by surgeons at academic meetings. Therefore, by applying video compression encoding technology (H.265/HEVC), we have developed the 8K-UHD video recorder “RESTAR R8” that achieves both 8K-UHD image quality and ling-time recording. This new recorder enables medical professionals not only to record 8K-UHD video in the same way as conventional medical recorders in the operating room, but also to record, edit and play back outside the operating room with utilizing the network connection. We would like to continue working on technology and solution development so that we can utilize the recorder not only in the operating room and medical education fields, but also in a wide range of solution fields such as digital video, security and manufacturing inspection fields where 8K-UHD video is expected to be used in the future.

Holography is the recording of the interference pattern of a reference and light reflected from or transmitted through an 3D object. In conventional digital holography, the interference intensity pattern is recorded on a digital camera. Recording reflection holograms using this device are usually not possible. In this paper, we outline a method to numerically convert digital transmission holograms to digital volume reflection holograms by simulating a reflection grating which incorporates a fast longitudinal variation along with information from the transmission hologram function. This longitudinal variation would from the interference of two counter propagating waves, similar to what would be physically recorded in a bulk medium for a volume reflection grating. Coupled wave theory is then used to read the simulated volume reflection hologram and reconstruct the object. Wavelength multiplexing is readily achieved in this simulated volume hologram recording. Volume reflection holography has the advantage of excellent wavelength selectivity during readout using multispectral or white light. We demonstrate digital volume reflection holography by numerically simulating digital transmission hologram recording using simple objects such as Gaussian beams at two different wavelengths. This is followed by experimentally recording the digital transmission holograms of two objects with different wavelengths and repeating the reflection hologram conversion and readout numerically. Digital volume reflection holography is expected to have applications in 3D color holographic displays.

Surface inspection of products has become an essential factor in improving appearance quality. Surface inspection is performed using the brightness deviation from the reference images or the neighboring pixels. If there is no anomaly, there is no deviation, but if there are anomalies, the deviation is generated. Detecting the anomaly on an object’s original shape is not easy. In this paper, to solve this problem, we propose a method of extracting the information of perpendicular norm at the boundary which is the shape information of the target object, and generating a transformed two-dimensional(2D) image using the pixel interpolation method. The transformed 2D image information is used as data that efficiently extracts anomalies. Furthermore, if an area in which a boundary can be extracted, anomalies can be detected by making a transformed 2D image of the neighboring region of the boundary. In order to verify the performance of the proposed method, experiments were conducted based on objects with anomalies on various shapes. It is necessary to acquire a high-resolution image of UHD or higher to detect detailed anomalies. We expect the anomaly detection algorithm proposed in this paper to enable surface inspection of areas that were difficult to inspect..

In 1985, the author found for the first time that an experimental pickup tube (camera tube) with an amorphous selenium (a-Se) photoconductive target exhibits high sensitivity with quantum efficiency in greatly excess of unity under an applied target electric field greater than 9x10⁷ V/m. This phenomenon results from a continuous and stable avalanche multiplication in the photoconductive target. We named the pickup tube with an amorphous photoconductive target operating in the avalanche-mode “HARP”: High-gain Avalanche Rushing amorphous Photoconductor. A color camera equipped with the HARP tubes with a target film thickness of 25 µm has a maximum sensitivity of 11 lx at F8. This means that the HARP camera is about 100 times as sensitive as that of CCD cameras for broadcasting. This ultra-high sensitivity HARP pickup tube was a powerful tool for reporting breaking news at night and other low-light conditions, the production of scientific programs, and numerous other application, including medical diagnoses, biotech research, and nighttime surveillance. It is expected that this high-sensitivity technology for image sensors will be useful for highsensitivity 8K UHD cameras in the near future.

We have developed a holographic three-dimensional (3D) display with a wider viewing zone than conventional planar holograms by using a non-planar optical element generating a diverging spherical wave with a wide spreadangle. The convex parabolic mirror and non-planar holographic optical elements were used as such non-planar optical elements. If the computer-generated holograms are designed properly considering the reflection on the non-planar optical elements, a 3D object can be reconstructed inside them as a virtual image. Viewers can observe 3D objects from the periphery of the 3D object, and optical experiments successfully demonstrated our proposed methods.

Given concerns that the new Intermediate Frequency that has been expanded by the ultra-high definition TV (In Japan, it is called New 4K8K satellite broadcasting) could interfere with other systems’ electromagnetic waves, the incorporation of fiber optics into broadcast networks has been receiving attention as a way to resolve this issue in a fundamental manner. I would like to take this opportunity to introduce the characteristics and capabilities of the POF system, which is a new broadcasting transmission system that makes it possible to easily incorporate fiber optics into networks.

One of the challenges that has been faced by holographic 3D display is the lack of 3D contents. To deal with the shortage of 3D contents, a 2D-to-3D algorithm is presented for the holographic 3D display. The 2D images are firstly classified into 3 categories by the features. The depth maps for different categories are obtained by different calculation models accordingly. The computer-generated holograms (CGHs) are calculated by the layer-based angular-spectrum approach. These CGHs can be reconstructed with obvious 3D depth cues in simulations and experiments.

Optical aberrations hinder the realization of high-quality near-eye displays. The imperfection of the optical components and the human eye causes image quality degradation. This invited paper introduces two recent works on aberration correction methods in holographic displays. The wave optics-based computer-generated hologram calculation method to correct the optical aberration from the eyepiece of the near-eye display is presented. In addition, the ray tracing-based vision-correcting holographic display for correcting the ocular aberration of the human eye is demonstrated.

We used the amplitude coding method of 3:16, that is, in a 4 * 4 pixel matrix, only three pixels are in the on state, and the remaining pixels are in the off state. In the collinear amplitude holographic data storage system, U-Net full convolution neural network is used to denoise the amplitude coded image obtained by the detector. The experimental results show that the bit error rate can be reduced to less than 1% from 10% and the image signal-to-noise ratio can be increased by more than 5 times.

Volume holograms exhibit the characteristic of multiple optical functions in a common area by multiple exposure in preparation. From the characteristic, it is expected to be applied to large capacity recording medium and diffractive optical elements with unique functions. In this study, volume holograms are investigated to apply to diffractive optical elements for high-definition imaging of nanostructure. The assumed volume holographic diffractive optical element exhibits a function that light waves from two-point sources with a distance shorter than the wavelength are diffracted as plane waves with different wave vectors. When a volume hologram is prepared by exposing the interference fringes consist of a point source light and a plane wave, a plane wave is diffracted by illuminating a point source light onto the volume hologram. However, the wave vector of the diffracted plane wave is changed and the diffraction efficiency is decreased by shifting the position of the point source light. By wave vector filtering, the diffracted plane wave from a point source at shifted position becomes not to be detected. A volume hologram can be prepared that the point source at the shifted position is diffracted as a plane wave with a different wave vector by multiple exposure. Then, two-point sources can be resolved. The distance between two-point sources is called shift-selectivity. For preparing the volume holographic optical element, a photopolymer with a thickness of 10 mm was used to obtain short shift selectivity. The photopolymer was exposed by using a semiconductor lase with a wavelength of 405 nm. In this condition, a shift selectivity of 100 nm was achieved.

Space-bandwidth product in digital holography is defined as a product of spatial dimension and bandwidth of the sampled space. This limitation results in a narrow field of view or a small eye-box in holographic near-eye display. Utilizing additional micro-structured or non-periodic optics is a well-known approach that bypasses this physical constraint. However, these approaches require precise alignment and suffer from low signal-to-noise ratio in the reconstructed holographic image. In this work, we propose a novel prototype of holographic near-eye display with wide field of view achieved by axially overlapped holographic projection. The feasibility of the proposed work is evaluated with simulation and experimental results