Rainbow Hologram Research Articles

Computer generated color rainbow holographic stereogram

In this research, a fast method to calculate the color rainbow holographic stereogram (CRHS) by taking full advantage of the sparsity of the frequency domain is demonstrated. The CRHS is a novel color rainbow hologram containing a large number of elemental CRHSs, where each elemental CRHS only reproduces the color light field information of local 3D color object. The color of the reconstructed color 3D image perceived by the human eye is determined by the spectrum of the reproduced dispersion of different elemental CRHSs that enter the human eye. The calculation of the CRHS is implemented with parallel computing by inversely Fourier transforming the frequency of each elemental CRHS. With the proposed method, the computation time for a resolution of 200k × 200k pixels and size of 64 × 64 mm CRHS is only 15.4 min for a color 3D model with 406k object points. The optical reconstruction with a white LED light illumination proves the effectiveness of our proposed method, which can be applied to the field of color holographic 3D display, advertising or holographic packaging.

U(rano)topia: spectral skies and rainbow holograms for silica aerogel artworks.

Micro/nano structuring in distinct chemical compositions has demonstrated added values which could be utilized in various modern applications and products through the lens of visual arts. Silica aerogel is a prominent example of such a nanostructure, with which we recently utilized to accommodate the unique design of high jewelry. Using its natural shades and transparent layers, silica aerogel can be described by the first author, a visual artist, as an extremely beautiful and ethereal material that closely resembles a piece of sky. Ultimately silica aerogel can be exploited as a sky-like material, and has been used in numerous collaborations amongst artists and scientists to bring to life concepts, like rainbow holograms on silica aerogel dried by high-temperature supercritical drying with methanol. In this short review, we show how such collaborations the authors have been proceeding are evoking developments in science and technology as well as in design, fashion and art industries. The series of the collaborative research has been contributing to the development of quality end products by merging new technologies, novel functional materials and innovative manufacturing processes with visual arts.

Recording a Hologram Transmitted over a Communication Channel on One Sideband

The paper presents experimental results on the recording and restoration of 3D holographic frames suitable for transmitting 3D holographic images with the frame rate required for TV images and a resolution of the Full HD standard and higher. The Patent RF No. 2707582 proposed a method for compressing holographic information and transmitting it using a procedure similar to SSB over conventional communication channels. In this work, the holographic information of a 3D portrait of a person, transmitted and received via the Wi-Fi communication channel, was restored in the form of a rainbow hologram, as one of a variety of holograms, by the computer addition of the carrier spatial frequency, and then hologram was actually produced on a photoresist. This technology can be used to create a holographic phototelegraph or, if there is a dynamic holographic display, to create a holographic television and 3D augmented reality.

Phase-only color rainbow holographic near-eye display.

Color rainbow holography can realize color holographic 3D display without speckle noise under white light illumination. However, traditional color rainbow holograms used for high-resolution static color 3D display or near-eye color display are amplitude-type, resulting in low diffraction efficiency due to the presence of conjugate light. In this Letter, a phase-only color rainbow holographic near-eye display is demonstrated. The calculation of a phase-only color rainbow hologram is realized by combining a band-limited diffraction and a bi-directional error diffusion algorithm with high-frequency blazed gratings coded to control longitudinal dispersion. When the wavelength of illumination light is deviated from the designated wavelength of the hologram, only a certain wavefront aberration is caused, but there is no conjugate light. The phase-only color rainbow holographic near-eye display of both a 2D color image and a 3D scene are implemented by optical experiments. It has potential applications in head-mounted 3D augmented reality displays without vergence-accommodation conflict.

Fast method for high-resolution holographic 3D display with white light as illumination

In this research, we propose a fast-computational light field image encoding method for a white light high-resolution full-parallax holographic 3D display and full-color rainbow holographic 3D display. With this method, a novel priority-based sequential rendering is used to improve the computation speed. The local visible 3D data is rendered at a higher priority and then used for rendering multiple local element light field images (EIs) at the holographic plane with the corresponding pinhole array behind the holographic plane. The EIs are independently coded as hogels by multiplying the corresponding phase function without using computation-intensive fast Fourier transform. This parallel computation method is implemented for both a full-parallax holographic 3D display and full-color rainbow holographic 3D display. An ultra high-resolution of a full-parallax hologram and a full-color rainbow hologram both at the resolution of 200 000 × 200 000 pixels only cost 14 min and 78 min, respectively. Our experimental results have also shown the effectiveness of the proposed high-resolution 3D display method.

Semi-permeable resonant aluminum gratings for structural coloration in transmission.

The novel type of diffraction gratings consists of a semi-permeable corrugated aluminum film with periods supporting first-order diffraction in the visible wavelength range. These gratings exhibit coloring of the transmitted zeroth order due to excitation of surface plasmons. The hue depends on the angle of incidence and may be adjusted by varying the grating period. Manufactured samples with motifs containing grating arrays of different periods demonstrate a wide range of achievable colors. The fabrication process is suited for scale-up to large area production, since the replication on plastic foils can be implemented as a cost-effective roll-to-roll process. These gratings have practical applications as security features, since they are fully compatible to widely used rainbow holograms.

Изучение нанорельефов и штампов для голографической защиты

This article describes the creation and study of high quality reliefs and stamps. The thickness of the relief is 40 nm. The created nanoreliefs were investigated by optical and atomic force microscopy. Several methods have been tested for their creation: dry etching, nanolithography and nanoprinting. The developed technology for the transfer of nanoreliefs on various surfaces is distinguished by the obtained high resolution about 10 nm and low energies of the used electron beam 1-150 μC/cm2. The obtained finished reliefs can be used in mints in the form of a high level security holograms, in photolithography for the manufacture of masks, in the creation of rainbow holograms, holographic gratings.

Shellac hologram

The results of experimental research of rainbow holograms made of edible shellac, analysis of diffraction efficiency and analysis of the hologram lifetime in various environmental conditions are reported in this work. The properties of shellac as a food biopolymer allow to use it for creation edible holographic coatings on food and pharmaceutical products. Edible shellac holograms can be use for creation images not using food dyes, original appearance, labels, sensors of shelf life and observance of storage regulations of products.

Wavelet Transform on Digital Rainbow Hologram based on Spectral Compression for Quality Enhancement in 3D Display Media

Wavelet Transform on Digital Rainbow Hologram based on Spectral Compression for Quality Enhancement in 3D Display Media

Large scale and high resolution computer generated synthetic color rainbow hologram

In this study, we propose a method for calculating a large scale high resolution synthetic color rainbow hologram using the frequency domain splicing technique. This method is motivated by the observation that if the plane wave is used as the reference light, the spectra of the three primary colors of the object light in the color rainbow hologram frequency domain are mutually separated frequency bands. According to this principle, the color views of different angles of a colored 3D object are separated and interpolated, and 2D Fourier transform is performed to form an object light spectrum distribution of the color rainbow hologram. Following the operation, efficient one-dimensional Fourier inverse transform in the row and column directions of the frequency is conducted. The proposed method is able to achieve a significant boost in terms of large scale high resolution hologram computational speed. We demonstrate that a synthetic color rainbow hologram with a size of 30 × 30 mm and a resolution of 94 340 × 94 340 is achieved through our holographic printing system with an unprecedented time of only 25 min. The method is also able to achieve a visually appealing computer generated white light color rainbow hologram, thus having great potential to be used for a practical holographic 3D display.

High Resolution Computer-Generated Rainbow Hologram

We have developed an output device for a computer-generated hologram (CGH) named a fringe printer, which can output a 0.35- μ m plane-type hologram. We also proposed several CGH with a fringe printer. A computer-generated rainbow hologram (CGRH), which can reconstruct a full color 3D image, is one of our proposed CGH. The resolution of CGRH becomes huge (over 50 Gpixels) due to improvement of the fringe printer. In the calculation, it is difficult to calculate the whole fringe pattern of CGRH at the same time by a general PC. Furthermore, since the fine pixel pitch provides a wide viewing angle in CGRH, object data, which are used in fringe calculation, should be created from many viewpoints to provide a proper hidden surface removal process. The fringe pattern of CGRH is calculated in each horizontal block. Therefore, the object data from several view points should be organized for efficient computation. This paper describes the calculation algorithm for huge resolution CGRH and its output results.

Peculiarities of rainbow holograms application on the surface of the caramel

Rainbow hologram may be applied on the candies made from isomalt, fructose, sugar and molasses. The composition of caramel affects on its optical properties and the ability to save the diffraction grating.

基于频域合成的计算机制半周视彩色彩虹全息

基于频域合成的计算机制半周视彩色彩虹全息

Characterization of the surface relief of film diffractive optical elements

The surface relief of film reflective diffractive optical elements (DOE) has been characterized by atomic force microscopy. The elements under study were fabricated using a variety of microfabrication techniques: traditional laser recoding of reflection rainbow holograms, Dot matrix and Kinemax technologies, and e-beam lithography. The influence of these technologies on the relief characteristics has been estimated. It has been shown that the choice of such technologies is defined by the necessity to obtain corresponding optical characteristics of diffractive optical elements.

Fast computer simulation of reconstructed image from rainbow hologram based on GPU

A fast computer simulation solution for rainbow hologram reconstruction based on GPU is proposed. In the commonly used segment Fourier transform method for rainbow hologram reconstruction, the computation of 2D Fourier transform on each hologram segment is very time consuming. GPU-based parallel computing can be applied to improve the computing speed. Compared with CPU computing, simulation results indicate that our proposed GPU computing can effectively reduce the computation time by as much as eight times.

Fabrication of digital rainbow holograms and 3-D imaging using SEM based e-beam lithography.

Here we present an approach for creating full-color digital rainbow holograms based on mixing three basic colors. Much like in a color TV with three luminescent points per single screen pixel, each color pixel of initial image is presented by three (R, G, B) distinct diffractive gratings in a hologram structure. Change of either duty cycle or area of the gratings are used to provide proper R, G, B intensities. Special algorithms allow one to design rather complicated 3D images (that might even be replacing each other with hologram rotation). The software developed ("RainBow") provides stability of colorization of rotated image by means of equalizing of angular blur from gratings responsible for R, G, B basic colors. The approach based on R, G, B color synthesis allows one to fabricate gray-tone rainbow hologram containing white color what is hardly possible in traditional dot-matrix technology. Budgetary electron beam lithography based on SEM column was used to fabricate practical examples of digital rainbow hologram. The results of fabrication of large rainbow holograms from design to imprinting are presented. Advantages of the EBL in comparison to traditional optical (dot-matrix) technology is considered.

High Performance Graded Rainbow Holograms via Two-Stage Sequential Orthogonal Thiol–Click Chemistry

Orthogonal, sequential “click” reactions were implemented to yield novel polymeric substrates with the ability to record holographic data. The base-catalyzed thiol–acrylate Michael “click” reaction was implemented to yield a writable, stage 1 polymeric substrate with glass transition temperatures (Tg) ranging from 0 to −26 °C and rubbery storage moduli (E′) from 11.1 to 0.3 MPa. The loosely cross-linked matrix also contained a novel high refractive index monomer 9-(2,3-bis(allyloxy)propyl)-9H-carbazole (BAPC) that did not participate in the thiol–Michael reaction but allowed for large index gradients to be developed within the network upon subsequent exposure to coherent laser beams and initiation of the radical-mediated thiol–ene reaction. The holographic gratings were recorded with 96% diffraction efficiency and ca. 2.4 cm/mJ of light sensitivity in 2 s under a 405 nm exposure with an intensity of 20 mW/cm2. Subsequent to pattern formation, via a thiol–allyl radical “click” photopolymerization initiated...

大视角真彩色全息图制作的新方法

In order to improve the color effect and the visual angle of hologram,based on the method of mirror images,a new technique is proposed to obtain a real color hologram with a large viewing angle by the combination of computer-generated hologram and optical hologram.There are two steps to realize the method:Firstly,computer-generated hologram H1r,H1g,H1bis yielded with three image objects.Secondly,a rainbow hologram H2is generated by optical ways.In terms of the reversibility of light path principle,an image with a wide viewing angle is reconstructed by reversing the reconstructed wave.The technique achieves a color reconstruction image with a wide viewing angle of 14°.The color effect and the stereoscopic effect of the reconstruction image is increased.

Holography and Art – Using rainbow hologram in my works

Holography can be understood as one of the more sophisticated subjects within the realm of modern art. Even after several years of study and application, understanding Holography simply does not get any easier. For that reason, instead of trying to discuss both the technical and the artistic aspects of holography, the emphasis will strictly be on the latter. Just like any other paradigm or medium capable of fascinating the human hearts, holography has changed the way I encounter the world. Changed perception of the world brought me feelings of child-like delight. Among the various subdivisions of holography, I hold Rainbow Hologram exceptionally close to my heart. Not only is it related to my previous works but its bright, crisp and various color movements are also depicted wonderfully in 3-dimension. I would like to share my fascination with rainbow hologram with you.

利用数值再现实现彩虹全息色差评价

In order to obtain color fidelity of reconstructed image before the computer generated rainbow hologram printed and reconstructed optically,a color difference test method based on numerical reconstruction is proposed.Firstly,the computer generated rainbow hologram is analyzed in special frequency domain.The relationships between reconstruction parameters and special frequency distribution are concluded.Then,the spectrum distributions of reconstructed images are obtained through simulated reconstruction of computer generated rainbow hologram by filtering in frequency domain.Moreover,the color difference of reconstructed image is calculated in CIE1976UCS uniform color space.Seven color cards are designed and with its computer generated rainbow holograms.The color differences are tested with the proposed method.The optical experiments are designed with the illumination of halogen light source.The results and analysis are presented and show that the proposed method is effective and fast way for the analysis of spectral distribution and color difference of computer generated rainbow hologram.