This PDF file contains the front matter associated with SPIE Proceedings Volume 10943, including the Title Page, Copyright Information, Table of Contents, Introduction, Author and Conference Committee lists

Phase-encoded multi-valued signal has advantages of the simultaneous increase of storage density and data transfer rate. However, to acquire the phase information, it is usually required that the diffracted image interferes with another plane wave because the imaging device cannot obtain the phase information directly. Such an additional process leads to complication of the optical system, and lowering the transfer rate due to the plurality of detection. To address this issue, we proposed a simple method of extracting phase-encoded signal by one image acquisition without using any other plane wave. This method utilizes inter-pixel crosstalk to retrieve the recorded phase. In the holographic data storage system, the rectangular aperture is usually inserted in the Fourier plane of the input image in order to limit the exposure area of the recording medium. Since this aperture is also acting as a low-pass filter, transmitted image is blurred and inter-pixel crosstalk occurs. At the boundary of pixels, the light waves of adjacent pixels interfere with each other, and its resultant intensity is determined by the relative phase between adjacent pixels. Therefore, if the known-phase pixels are properly arranged in the input image, we can determine the unknown phase from the intensity at the boundary. In order to estimate the reconstruction ability of our proposed method, we have numerically investigated the pixel error rate of 4-level phase encoded signal as a function of aperture size and detecting area at the boundary. We also confirmed the validity of our proposed method experimentally.

In our previous work, digital holographic topography has been used to investigate the depth pattern of different surfaces. Two-wavelength digital holography has been used to resolve depth variations on surfaces, which are in the order of several microns to centimeters. These holograms are reconstructed numerically by Fresnel diffraction to retrieve phase and intensity information, which reveals the three-dimensional topographic surface details. To determine the similarity/difference between two 3D objects, we have recently proposed a novel technique involving 2D correlation of holograms, where holograms constructed from sets of point sources in 3D space were simulated to demonstrate the feasibility of this method. Crosscorrelation of holograms can also be used to authenticate the quality of holograms, and for 3D image encryption. In this work, correlation of holograms, both computer-generated, as well as optically recorded from diffuse objects, will be investigated. Computer generated holograms are also created to mimic surface roughness of real 3D objects. Correlation can be used to evaluate the quality of the surfaces, such as objects fabricated by 3D manufacturing techniques.

Three-dimensional (3D) model with high-quality texture is a powerful way to interact between virtual and reality 3D scene. It has significant applications in digital preservation of cultural heritage, virtual reality / augmented reality (VR/AR), medical imaging and other domains. High-quality texture reconstruction is one of the essential elements for 3D model. Due to the camera pose error and inaccurate model, current texture reconstruction methods could not eliminate the artifacts like blurring, ghosting and discontinuity. In this work, multi-view high-definition images are captured for texture mapping. Normal-weight, depth-weight and edge-weight parameter are introduced to evaluate texture color confidence, respectively. The normalized weight factors are multiplied to generate a comprehensive weight parameter. By taking a weighted average of projected texture images, discontinuity of texture can be smoothed to a large extent. For large misalignment, bidirectional similarity (BDS) function, which represent the structural similarity between two images, are utilized to improve the texture image. The energy function is composed of two terms. One is Euclidean distance between target texture image and merged texture image. The other is BDS between target texture image and original texture image. By minimizing the energy function, the texture image could generate small local displacement while retaining the original structural information. The target and merged images are optimized alternately, the target image is calculated by patch-match algorithm, and the merged image is derived from weighted average of target images. The method we proposed could produce seamless texture comparing with Markov random field (MRF) algorithm. The definition could be higher than the camera parameter optimization algorithm. The experimental results show that structural similarity (SSIM) between the reconstructed images and the ground truth is higher than traditional algorithms. When dealing with inaccurate models with less than 10,000 facets, the SSIM value could be doubled compared with current algorithms.

Printable organic solid-state devices, including organic light-emitting diodes (OLEDs) and organic thin-film transistors (OTFTs) present a paradigm shift in manufacturing, cost and environmental impact when compared to the conventional inorganic technologies. OLEDs offer great versatility in the design of lighting systems based on large-area diffused light sources. In recent years, smarter lighting concepts have emerged at the crossroad of display technology and lighting that enable the control of the spatial distribution of light in real time. This adaptive illumination is enabled by combining segmented OLEDs with OTFTs. For these concepts to come to fruition, it is critical that further advances be made in improving the efficacy and stability of OLEDs and simultaneously in enhancing the performance and reliability of OTFTs. In this talk, we will discuss recent advances in developing new thermally activated delayed fluorescent materials and recent progress in OTFTs. In particular, we report on an exhaustive characterization of OTFTs with an ultra-thin bilayer gate dielectric comprising the amorphous fluoropolymer CYTOP and an Al2O3: HfO2 nanolaminate. The bilayer geometry results in two distinct aging mechanisms that through a compensation effect, yields devices with very low threshold voltage shifts. Modeling with a double stretched-exponential model predicts threshold voltage shift values in the range of 0.1 – 0.25 V over a period of ten years even at temperatures of 55 °C. The microcrystalline OTFTs with a bilayer gate dielectric exhibit carrier mobility values up to 1.6 cm2 V-1 s-1, a threshold voltage stability that is comparable or superior to that expected from commercial TFT technologies, and excellent environmental and thermal stability even after prolonged immersion in water.

We developed a modulation transfer function (MTF) measurement system that analyzes the edge responses of a sampled imaging system in real time. The MTF can be continuously observed while operating the iris, focus, and zoom. This system accurately estimates the edge angle and selects a binning phase from a small number of binning phases to improve the precision of the MTF estimation. Furthermore, it incorporates a simplified method that approximates the MTF without edge angle estimation and the following subpixel binning, enabling the analysis of nonstraight edges. This system is applicable to multiple edges in arbitrary directions, unlike the conventional ISO 12233 edge-based method, in which only a near-vertical or near-horizontal edge is applicable. The analysis of edge responses on a starburst chart yields a contour plot of multidirectional MTFs that enables direct observation of the anisotropy due to the performance and conditions of the camera and lens (e.g., misalignment of the optical components), as well as the pixel arrangement of the image sensor and image processing method applied (e.g., Bayer color filter array demosaicing). Further, this system can also measure camera noise while adjusting the MTF with an edge enhancement filter.

The paradigm theorem of light field optics is different from that of conventional imaging optics. The conditions for rays in a 3D space are reconstructed from the light field data shown on a 2D high definition flat display through the lens array. A light field display consists of a flat display and lens array attached on its screen. The light field display can be regarded as a transformation system for the light field data. Further, the light field data can be considered as 3D space information in another domain. It contains information of rays in a space, and a point light source in space is expressed as information of many rays that go through the point light source. A point light source in space represents a set of many point light sources, and each ray that composes a point light source should be described in the light field data. Therefore, the light field flat display requires a much higher resolution as compared to that required by a conventional imaging device, on which a point light source can be expressed by a single pixel. In this study, we developed various light field displays using high definition flat displays, introduced the theorem of light field display, and reported the examples of our experimental light field displays.

Recently, technology for high resolution device has improved. Accordingly, it is predicted that the demand is increasing. The device such as high-resolution display with amount of data requires large capacity data storage to store the data. Therefore, we considered that holographic data storage that is expected as large capacity can be used as storage device of UHD. However, many errors generate by noises in high density holographic data storage. It is supposed errors can be corrected by clarifying the cause of noises. In order to analyze the noises and correct the errors, light propagation analysis is required. Although several light propagation analysis methods are established, these are not suitable for analyzing holographic data storage. One of the reasons why not suitable is that heavy computation loads can be time-consuming in conventional methods because the thickness of volume holograms are much thicker than the wavelength of propagating light. In this study, we propose light propagation analysis method based on analytic function. In addition, we investigate method that can calculate light propagation in holographic data storage using the method. In holographic data storage, the information is recorded as electric susceptibility distribution of recording medium. This study introduces a parameter related light intensity and sensitive of medium and the Maxwell’s wave equation is expanded by Born-expansion using the parameter. Then, solutions of the wave equation can be solved analytically. Therefore, behavior of light wave in volume hologram can be expressed. We analyze the noises and investigate methods correcting errors by using this method.

Transparent polyimides (TPIs) have a possibility for the using of foldable displays because of their enhanced flex resistance and high thermal stability. On the other hand, TPIs have high birefringence (= high out of plane retardation (Rth)) thus it causes the rainbow mura if when a display using a conventional TPI film was watched through polarized sunglasses. It was reported that optical films were decreased the retardation by doping with inorganic crystals, that have rod-shaped and the opposite birefringence to that of the polymers. However, if particle size and amount of added crystals are not optimized, its haze values are increased. The purpose of this article is to fabricate the low retardation TPI films with inorganic birefringent crystals such as strontium carbonate (SrCO3) crystals with their rod-like shape and opposite birefringence. We found small and nearly monodispersed SrCO3 suggested low Rth of 17 nm and low haze TPI films. The Rth value of this film is almost same of triacetylcellulose film, which is widely used in display as low retardation film. This low retardation film was obtained by casting method from the under 100 nm SrCO3 dispersed TPI solution.

A spatial light modulator (SLM) is the key component for a digital holographic display system. It requires both ultrahigh- resolution fine pixel integration and large-area panel to get a wide viewing angle and large realistic 3D images. Because these requirements collide with each other, it is very difficult to develop the digital holography system satisfying the standard of the general public. Unlike conventional SLMs, which are based on small size semiconductor ICs, we have developed larger size, highresolution SLM on glass (SLMoG) using both semiconductor and display fabrication technologies. 1-μm channel length oxide TFTs are integrated for pixel switching and the liquid crystal (LC) of high refractive index anisotropy was used to modulate the phase of incident light. Multiple high-speed interface boards and large channel driver ICs are used to drive large size holographic image data. 2.16-inch 16K SLMoG panel with 3-μm horizontal pixel pitch was successfully developed for the first time. Without the aid of additional instruments, it was possible to observe a simple 3D objects with the naked eye. For even wider viewing angle and larger size SLMoG, the proof of concept SLMoG panel for still image hologram with smaller pixel pitches was developed to evaluate cross-talk between adjacent LC pixels.

The International Telecommunication Union Radiocommunication Sector (ITU-R) Recommendation BT.2020 was standardized for ultra-high definition television (UHDTV). The BT.2020 specifications are 8K resolutions, a wide color gamut, and 120-Hz driving. The BT.2020 color gamut is defined from the three primary monochrome colors. Therefore, changing the light source of the backlight from conventional light-emitting diodes (LEDs) to lasers is necessary. We succeeded in prototyping a 17-inch 8K liquid crystal display (LCD) that satisfies the BT.2020 specifications. The pixel density of the 17-inch 8K display is 510 ppi, and the color gamut covers 97% of BT.2020. The liquid crystal response time is 5 ms, which is sufficient for the 120-Hz driving. To achieve the above-mentioned specifications, we developed the following technologies. To expand the color gamut, an RGB laser backlight was used. A backlight with conventional LEDs as light sources only covered 52% of BT.2020. To reduce response time, we applied a faster in-plane switching LCD (IPS-LCD) named short-range lurch control (SLC) IPS-LCD. We succeeded in realizing a blur-free display using the SLC IPS.

We developed high efficiency see-through glasses in a compact structure using waveguides and embedded coupling wavelength selective filters. The design provides a solution for the optical combiner offering high see-through transparency and high luminance image with low loss. A prototype of the see-through glasses based on the proposed design was fabricated and the optical properties were measured by experiments. Through the prototype, both the overlaid virtual image and the real ambient view can be seen with high resolution.

In this paper, an end-to-end optimization of optics and image processing which consider angle of incidences is proposed. By considering the various angle of incidences to the optics, the optimized system can capture and reconstruct a real image even for non-paraxial input light. The optimization pipeline includes diffractive wave simulation, effects from wavelength differences, and image processing. Several points spread functions are used to simulate captured images for tilted input light. Captured images are reconstructed by different deconvolution kernels according to the sub-section of the images. To apply the system to real-world experiments, we consider the limitation of diffraction angle for given memory constraints and differences between manufacturing and sensor resolution by using Fourier optics. We demonstrate the simulation results of the proposed approach by applying it to various angle of incidences.