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Chengcheng Chang, Xudong Chen, Ziyang Chen, Zhili Lin, Xiaoyan Li, Jixiong Pu
We demonstrate, to the best of our knowledge, a new kind of laser, called a partially coherent digital laser, producing nonuniformly correlated partially coherent light beams by "playing a video" inside the cavity directly. In this laser, a spatial light modulator (SLM) with dynamic phase modulation acts as a cavity mirror. The coherence degree distribution of the output beams can be controlled simply by varying the waists of the computer-generated holograms on the SLM. The experimental results show that the coherence degree between two points on the observation plane is not only dependent on the distance between them, but also on the positions that are observed across the beam...
June 1, 2018: Applied Optics
Enliang Wang, Yonghao Liang, Hailiang Li, Changqing Xie
We present composited holograms to realize the azimuthal interference of cylindrical optical lattices (COLs) and the flower modes (FMs) of Fourier transform-truncated Bessel beams (FT-TBB). Three types of binarization operations are evaluated for the composited holograms generated by two FT-TBB with independent topological charges l1 and l2 and the same radial index p=1. Both the numerical solutions and experimental results demonstrate that the four types of COLs and FMs, namely, the conventional COL, interleaved COL, flower-core FM, and polygon-core FM, can be produced by the Fourier transformation of the composited holograms with the same radial index p=1 and topological combinations ||l1 |-|l2 ||<2, ||l1 |-|l2 ||=2, ||l1 |-|l2 ||=3, and ||l1 |-|l2 ||=4, respectively...
June 1, 2018: Applied Optics
Dong-Wook Kim, Yoon-Hyuk Lee, Young-Ho Seo
This publisher's note corrects the author affiliations in Appl. Opt.57, 3511 (2018)APOPAI0003-693510.1364/AO.57.003511.
June 1, 2018: Applied Optics
Zhao-Xiang Fang, Hong-Ze Zhao, Yue Chen, Rong-De Lu, Li-Qun He, Pei Wang
We report on a novel kind of accelerating beams that follow parabolic paths in free space. In fact, this accelerating peculiar polygon beam (APPB) is induced by the spectral phase symmetrization of the regular polygon beam (RPB) with five intensity beam (RPB) with five intensity peaks, and it preserves a peculiar symmetric structure during propagation. Specially, such beam not only exhibits autofocusing property, but also possesses two types of accelerating intensity maxima, i.e., the cusp and spot-point structure, which does not exist in the previously reported accelerating beams...
June 5, 2018: Scientific Reports
Bahram Javidi, Adam Markman, Siddharth Rawat, Timothy O'Connor, Arun Anand, Biree Andemariam
We present a spatio-temporal analysis of cell membrane fluctuations to distinguish healthy patients from patients with sickle cell disease. A video hologram containing either healthy red blood cells (h-RBCs) or sickle cell disease red blood cells (SCD-RBCs) was recorded using a low-cost, compact, 3D printed shearing interferometer. Reconstructions were created for each hologram frame (time steps), forming a spatio-temporal data cube. Features were extracted by computing the standard deviations and the mean of the height fluctuations over time and for every location on the cell membrane, resulting in two-dimensional standard deviation and mean maps, followed by taking the standard deviations of these maps...
May 14, 2018: Optics Express
Jiwei Zhang, Siqing Dai, Jinzhan Zhong, Teli Xi, Chaojie Ma, Ying Li, Jianglei Di, Jianlin Zhao
Surface plasmon holographic microscopy (SPHM), which combines surface plasmon microscopy with digital holographic microscopy, can be applied for amplitude- and phase-contrast surface plasmon resonance (SPR) imaging. In this paper, we propose an improved SPHM with the wavelength multiplexing technique based on two laser sources and a common-path hologram recording configuration. Through recording and reconstructing the SPR images at two wavelengths simultaneously employing the improved SPHM, tiny variation of dielectric refractive index in near field is quantitatively monitored with an extended measurement range while maintaining the high sensitivity...
May 14, 2018: Optics Express
Zi Wang, Guoqiang Lv, Qinbin Feng, Anting Wang, Hai Ming
We proposed a simple and fast algorithm for computer-generated hologram (CGH) based on pinhole-type II using a look-up table. The method consists of two steps: in the first step, the unity amplitude diffraction pattern of the center pinhole on hologram plane is pre-calculated and stored as many sub-regions. Secondly, diffraction patterns for other pinholes are obtained by simply shifting and tiling the pre-calculated sub-regions, and the final CGH is obtained by adding them all together. The calculation time is short because only addition and multiplication of the stored diffraction pattern are required...
May 14, 2018: Optics Express
Juanmei Hu, Yimin Lou, Fengmin Wu, Aixi Chen
The imaging principles and phenomena of integral imaging technique have been studied in detail using geometrical optics, wave optics, or light filed theory. However, most of the conclusions are only suit for the integral imaging systems using diffused illumination. In this work, a kind of twin imaging phenomenon and mechanism has been observed in a non-diffused illumination reflective integral imaging system. Interactive twin images including a real and a virtual 3D image of one object can be activated in the system...
May 14, 2018: Optics Express
David B Ruffner, Fook Chiong Cheong, Jaroslaw M Blusewicz, Laura A Philips
Micrometer sized particles can be accurately characterized using holographic video microscopy and Lorenz-Mie fitting. In this work, we explore some of the limitations in holographic microscopy and introduce methods for increasing the accuracy of this technique with the use of multiple wavelengths of laser illumination. Large high index particle holograms have near degenerate solutions that can confuse standard fitting algorithms. Using a model based on diffraction from a phase disk, we explain the source of these degeneracies...
May 14, 2018: Optics Express
Peng Xia, Shien Ri, Qinghua Wang, Hiroshi Tsuda
A thermal deformation measurement system based on calibrated phase-shifting digital holography is proposed. Two synchronized ordinary CMOS cameras are used in the calibrated phase-shifting digital holography system. One is to record the holograms including the object information, and the other is to record the interference fringes to evaluate phase-shifting errors. The calibrated phase-shifting digital holography can provide the high quality reconstructed images which are applied to calculate the thermal deformation of the object...
May 14, 2018: Optics Express
Yu Zhao, Ki-Chul Kwon, Munkh-Uchral Erdenebat, Md-Sifatul Islam, Seok-Hee Jeon, Nam Kim
The calculation of realistic full-color holographic displays is hindered by the high computational cost. Previously, we suggested a point cloud gridding (PCG) method to calculate monochrome holograms of real objects. In this research, a relocated point cloud gridding (R-PCG) method is proposed to enhance the reconstruction quality and accelerate the calculation speed in GPU for a full-color holographic system. We use a depth camera to acquire depth and color information from the real scene then reconstruct the point cloud model virtually...
May 20, 2018: Applied Optics
Makoto Okui, Koki Wakunami, Ryutaro Oi, Yasuyuki Ichihashi, Boaz Jessie Jackin, Kenji Yamamoto
To replicate holograms, contact copying has conventionally been used. In this approach, a photosensitive material is fixed together with a master hologram and illuminated with a coherent beam. This method is simple and enables high-quality copies; however, it requires a large optical setup for large-area holograms. In this paper, we present a new method of replicating holograms that uses a relatively compact optical system even for the replication of large holograms. A small laser spot that irradiates only part of the hologram is used to reproduce the hologram by scanning the spot over the whole area of the hologram...
May 20, 2018: Applied Optics
Ryoichi Horisaki, Ryosuke Takagi, Jun Tanida
We present a method for computer-generated holography based on deep learning. The inverse process of light propagation is regressed with a number of computationally generated speckle data sets. This method enables noniterative calculation of computer-generated holograms (CGHs). The proposed method was experimentally verified with a phase-only CGH.
May 10, 2018: Applied Optics
José A Rodrigo, Tatiana Alieva
A scalar polymorphic beam is designed with independent control of its intensity and phase along a strongly focused laser curve of arbitrary shape. This kind of beam has been found crucial in the creation of freestyle laser traps able to confine and drive the motion of micro/nano-particles along reconfigurable 3D trajectories in real time. Here, we present and experimentally prove the concept of vector polymorphic beam adding the benefit of independent design of the light polarization along arbitrary curves...
May 16, 2018: Scientific Reports
Christoph A Agten, Cyrill Dennler, Andrea B Rosskopf, Laurenz Jaberg, Christian W A Pfirrmann, Mazda Farshad
OBJECTIVES: The aim of this study was to assess feasibility and accuracy of augmented reality-guided lumbar facet joint injections. MATERIALS AND METHODS: A spine phantom completely embedded in hardened opaque agar with 3 ring markers was built. A 3-dimensional model of the phantom was uploaded to an augmented reality headset (Microsoft HoloLens). Two radiologists independently performed 20 augmented reality-guided and 20 computed tomography (CT)-guided facet joint injections each: for each augmented reality-guided injection, the hologram was manually aligned with the phantom container using the ring markers...
May 8, 2018: Investigative Radiology
Xiaohu Zhang, Xiong Li, Jinjin Jin, Mingbo Pu, Xiaoliang Ma, Jun Luo, Yinghui Guo, Changtao Wang, Xiangang Luo
Composed of ultrathin metal or dielectric nanostructures, metasurfaces can manipulate the phase, amplitude and polarization of electromagnetic waves at a subwavelength scale, which is promising for flat optical devices. In general, metasurfaces composed of space-variant anisotropic units are sensitive to the incident polarization due to the inherent polarization dependent geometric phase. Here, we implement polarization-independent broadband metasurface holograms constructed by polarization-dependent anisotropic elliptical nanoholes by elaborate design of complex amplitude holograms...
May 8, 2018: Nanoscale
Dong-Wook Kim, Yoon-Hyuk Lee, Young-Ho Seo
A huge amount of computation is required to generate a hologram using a computer. In order to speed up the computer-generated-hologram (CGH) operation, we use a parallel programming technique using a general purpose graphic processing unit (GPGPU). In this paper, we propose three techniques to improve CGH performance in the condition using GPU. The first is to remove the memory bottleneck by allocating shared memory and a dedicated thread for this process, and the second is to optimize the block allocation within the GPU using a hologram pixel-based method...
May 1, 2018: Applied Optics
Juan Deng, Zile Li, Guoxing Zheng, Jin Tao, Qi Dai, Liangui Deng, Ping'an He, Qiling Deng, Qingzhou Mao
Metasurfaces consist of dielectric nanobrick arrays with different dimensions in the long and short axes can be used to generate different phase delays, predicting a new way to manipulate an incident beam in the two orthogonal directions separately. Here we demonstrate the concept of depth perception based three-dimensional (3D) holograms with polarization-independent metasurfaces. 4-step dielectric metasurfaces-based fan-out optical elements and holograms operating at 658 nm were designed and simulated. Two different holographic images with high fidelity were generated at the same plane in the far field for different polarization states...
April 30, 2018: Optics Express
F F Qin, Z Z Liu, Z Zhang, Q Zhang, J J Xiao
Due to the abilities of manipulating the wavefront of light with well-controlled amplitude, and phase and polarization, optical metasurfaces are very suitable for optical holography, enabling applications with multiple functionalities and high data capacity. Here, we demonstrate encoding two- and three-dimensional full-color holographic images by an ultrathin metasurface hologram whose unit cells are subwavelength nanoslits with spatially varying orientations. We further show that it is possible to achieve full-color holographic multiplexing with such kind of geometric metasurfaces, realized by a synthetic spectrum holographic algorithm...
April 30, 2018: Optics Express
Darshika Singh, Rakesh Kumar Singh
The recording and reconstruction of the Stokes parameter is of paramount importance for the description of the vectorial interference of light. Polarization holography provides a complete vectorial wavefront, however, direct recording and reconstruction of the hologram is not possible in a situation where the object is located behind the random scattering layer. The Stokes holography plays an important role in such situations and makes use of the Fourier transform relation between the Stokes parameters (SPs) at the scattering plane and the generalized Stokes parameters (GSPs) of the random field...
April 16, 2018: Optics Express
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