Acceleration of polygon-based computer-generated holograms using look-up tables and reduction of the table size via principal component analysis

Author(s):

Wang, Fan; Shimobaba, Tomoyoshi; Zhang, Yaping; Kakue, Takashi & Ito, Tomoyoshi

Abstract:

“In this study, we first analyze the fully analytical frequency spectrum solving method based on three-dimensional affine transform. Thus, we establish a new method for combining look-up tables (LUTs) with polygon holography. The proposed method was implemented and proved to be accelerated about twice compared to the existing methods. In addition, principal component analysis was used to compress the LUTs, effectively reducing the required memory without artifacts. Finally, we calculated very complex objects on a graphics processing unit using the proposed method, and the calculation speed was higher than that of existing polygon-based methods.”

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Publication: Optics Express
Issue/Year: Optics Express, Volume 29; Number 22; Pages 35442; 2021
DOI: 10.1364/oe.435966

Fast calculation of computer generated hologram based on single Fourier transform for holographic three-dimensional display

Author(s):

Chang, Chenliang; Zhu, Dongchen; Li, Jiamao; Wang, Di; Xia, Jun & Zhang, Xiaolin

Abstract:

“We present an efficient method for the fast calculation of computer generated hologram (CGH). The 3D object is split into sub-layers according to its depth information. A 2D all-in-focus image is generated by sequential tiling all the layers in one plane. A Fourier hologram that contains all the information of 3D object is calculated from the fast Fourier transform (FFT) of the reassembled 2D image. By multiplying a pre-calculated multifocal off-axis digital phase mask (DPM) to the Fourier hologram, the content of each layer is axially relocated to different depth in the Fourier transform optical system to reconstruct the 3D object. The computation speed of the proposed method is greatly improved with only single FFT calculation process. Both of simulation and experimental results proves the validation of the proposed method.”

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Publication: Displays
Issue/Year: Displays, Volume 69; Pages 102064; 2021
DOI: 10.1016/j.displa.2021.102064

Hologram computation using the radial point spread function

Author(s):

Yasuki, Daiki; Shimobaba, Tomoyoshi; Makowski, Michal; Suszek, Jaroslaw; Kakue, Takashi & Ito, Tomoyoshi

Abstract:

“Holograms are computed by superimposing point spread functions (PSFs), which represent the distribution of light on the hologram plane. The computational cost and the spatial bandwidth product required to generate holograms are significant; therefore, it is challenging to compute high-resolution holograms at the rates required for videos. Among the possible displays, fixed-eye-position holographic displays, such as holographic head-mounted displays, reduce the spatial bandwidth product by fixing eye positions while satisfying almost all human depth cues. In eye-fixed holograms, by calculating a part distribution of the entire PSF, we observe reconstructed images that maintain the image quality and the depth of focus almost as high as those generated by the entire PSF. In this study, we accelerate the calculation of eye-fixed holograms by engineering the PSFs. We propose cross and radial PSFs, and we determine that, out of the two, the radial PSFs have a better image quality. By combining the look-up table method and the wavefront-recording plane method with radial PSFs, we show that the proposed method can rapidly compute holograms.”

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Publication: Applied Optics
Issue/Year: Applied Optics, Volume 60; Number 28; Pages 8829; 2021
DOI: 10.1364/ao.437777

Holographic near-eye display based on complex amplitude modulation with band-limited zone plates

Author(s):

Chen, Yun; Hua, Minjie; Zhang, Tianshun; Zhou, Mingxin; Wu, Jianhong & Zou, Wenlong

Abstract:

“A holographic near-eye display (NED) system based on complex amplitude modulation (CAM) with band-limited zone plates is proposed. The whole system mainly consists of a phase-only spatial light modulator (SLM), an Abbe-Porter filter system, an eyepiece, and an image combiner. The point source method based on band limited zone plates is used to accurately control the bandwidth of the target complex amplitude. The effects of intensity modulation coefficient γ in the frequency-filtering method on the intensity and the quality of reconstructed images are analyzed, which provide a judgment basis for selecting the appropriate value of γ. We also derive the expressions of the field of view (FOV) and exit pupil of the NED system. Since the holographic image is magnified in two steps in this system, the large FOV can be obtained. The optical experimental results show that the proposed system can provide a dynamic holographic three-dimensional (3D) augmented reality (AR) display with a 23.5°horizontal FOV.”

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Publication: Optics Express
Issue/Year: Optics Express, Volume 29; Number 14; Pages 22749; 2021
DOI: 10.1364/oe.431032

Vision-correcting Holographic Display: Evaluation of Aberration Correcting Hologram

Author(s):

Kim, Dongyeon; Nam, Seung-Woo; Bang, Kiseung; Lee, Byounghyo; Lee, Seungjae; Jeong, Youngmo; Seo, Jongmo & Lee, Byoungho

Abstract:

“Vision-correcting displays are key to achieving physical and physiological comforts to the users with refractive errors. Among such displays are holographic displays, which can provide a high-resolution vision-adaptive solution with complex wavefront modulation. However, none of the existing hologram rendering techniques have considered the optical properties of the human eye nor evaluated the significance of vision correction. Here, we introduce vision-correcting holographic display and hologram acquisition that integrates user-dependent prescriptions and a physical model of the optics, enabling the correction of on-axis and off-axis aberrations. Experimental and empirical evaluations of the vision-correcting holographic displays show the competence of holographic corrections over the conventional vision correction solutions.”

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Publication: Biomedical Optics Express
Issue/Year: Biomedical Optics Express,Vol. 12, Issue 8, pp. 5179-5195, 2021
DOI: 10.1364/boe.433919

Single-shot digital multiplexed holography for the measurement of deep shapes

Author(s):

Kozacki, Tomasz; Mikuła-Zdańkowska, Marta; Martinez-Carranza, Juan & Idicula, Moncy Sajeev

Abstract:

“This work develops a single-shot holographic profilometer that enables shape characterization of discontinuous deep surfaces. This is achieved by combining hologram frequency multiplexing and an illumination technique of complex amplitude in multi-incidence angle profilometer. Object illumination is carried out from seven directions simultaneously, where the radial angular coordinates of illumination plane waves obey the geometric series. It is shown that: (i) the illumination pattern provides the required frequency separation of all object wavefronts in transverse frequency space, which is necessary for hologram demultiplexing, and (ii) numerical generation of longitudinal scanning function (LSF) is possible, which has large measurement range, high axial resolution, and small side lobes. Low side lobes of LSF and the developed multiplexed field dependent aberration compensation method are essential to minimize the negative influence of speckle noise of single-shot capture on the measurement result. The utility of the proposed method is demonstrated with experimental measurement of heights of two step-like objects.”

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Publication: Optics Express
Issue/Year: Optics Express, Volume 29; Number 14; Pages 21965; 2021
DOI: 10.1364/oe.428419

DL-SI-DHM: a deep network generating the high-resolution phase and amplitude images from wide-field images

Author(s):

Meng, Zhang; Pedrini, Giancarlo; Lv, Xiaoxu; Ma, Jun; Nie, Shouping & Yuan, Caojin

Abstract:

“Structured illumination digital holographic microscopy (SI-DHM) is a high-resolution, label-free technique enabling us to image unstained biological samples. SI-DHM has high re- quirements on the stability of the experimental setup and needs long exposure time. Furthermore, image synthesizing and phase correcting in the reconstruction process are both challenging tasks. We propose a deep-learning-based method called DL-SI-DHM to improve the recording, the reconstruction efficiency and the accuracy of SI-DHM and to provide high-resolution phase imaging. In the training process, high-resolution amplitude and phase images obtained by phase-shifting SI-DHM together with wide-field amplitudes are used as inputs of DL-SI-DHM. The well-trained network can reconstruct both the high-resolution amplitude and phase images from a single wide-field amplitude image. Compared with the traditional SI-DHM, this method significantly shortens the recording time and simplifies the reconstruction process and complex phase correction, and frequency synthesizing are not required anymore. By comparsion, with other learning-based reconstruction schemes, the proposed network has better response to high frequencies. The possibility of using the proposed method for the investigation of different biological samples has been experimentally verified, and the low-noise characteristics were also proved.”

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Publication: Optics Express
Issue/Year: Optics Express, Volume 29; Number 13; Pages 19247; 2021
DOI: 10.1364/oe.424718

Caustic Interpretation of the Abruptly Autofocusing Vortex beams

Author(s):

Xiao, Na; Xie, Chen; Jia, Erse; Li, Jiaying; Giust, Remo; Courvoisier, François & Hu, Minglie

Abstract:

“We propose an effective scheme to interpret the abruptly autofocusing vortex beam. In our scheme, a set of analytical formulae are deduced to well predict not only the global caustic, before and after the focal plane, but also the focusing properties of the abruptly autofocusing vortex beam, including the axial position as well as the diameter of focal ring. Our analytical results are in excellent agreement with both numerical simulation and experimental results. Besides, we apply our analytical technique to the fine manipulation of the focusing properties with a scaling factor. This set of methods would be beneficial to a broad range of applications such as particle trapping and micromachinings.”

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Publication: Optics Express
Issue/Year: Optics Express, Volume 29; Number 13; Pages 19975; 2021
DOI: 10.1364/oe.430497

Fourier horizontal parallax only computer and digital holography of large size

Author(s):

Kozacki, Tomasz; Martinez-Carranza, Juan; kuko{l}owicz, Rafa{l} & Chlipa{l}a, Maksymilian

Abstract:

“Registration and reconstruction of high-quality digital holograms with a large view angle are intensive computer tasks since they require the space-bandwidth product (SBP) of the order of tens of gigapixels or more. This massive use of SBP severely affects the storing and manipulation of digital holograms. In order to reduce the computer burden, this work focuses on the generation and reconstruction of very large horizontal parallax only digital holograms (HPO-DHs). It is shown that these types of holograms can preserve high quality and large view angle in x direction while keeping a low use of SBP. This work first proposes a numerical technique that allows calculating very large HPO-DHs with large pixel size by merging the Fourier holography and phase added stereogram algorithm. The generated Fourier HPO-DHs enable accurate storing of holographic data from 3D objects. To decode the information contained in these Fourier HPO-DHs (FHPO-DHs), a novel angular spectrum (AS) technique that provides an efficient use of the SBP for reconstruction is proposed. Our reconstruction technique, which is called compact space bandwidth AS (CSW-AS), makes use of cylindrical parabolic waves that solve sampling issues of FHPO-DHs and AS. Moreover, the CSW-AS allows for implementing zero-padding for accurate wavefield reconstructions. Hence, suppression of aliased components and high spatial resolution is possible. Notably, the imaging chain of Fourier HPO-DH enables efficient calculation, reconstruction and storing of HPO holograms of large size. Finally, the accuracy and utility of the developed technique is proved by both numerical and optical reconstructions.”

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Publication: Optics Express
Issue/Year: Optics Express, Volume 29; Number 12; Pages 18173; 2021
DOI: 10.1364/oe.421186

Aberration-free digital holographic phase imaging using the derivative-based principal component analysis

Author(s):

Lai, Xiaomin; Xiao, Sheng; Xu, Chen; Fan, Shanhui & Wei, Kaihua

Abstract:

“Significance: Digital holographic microscopy is widely used to get the quantitative phase information of transparent cells.

Aim: However, the sample phase is superimposed with aberrations. To quantify the phase information, aberrations need to be fully compensated.

Approach: We propose a technique to obtain aberration-free phase imaging, using the derivative-based principal component analysis (dPCA).

Results: With dPCA, almost all aberrations can be extracted and compensated without requirements on background segmentation, making it efficient and convenient.

Conclusions: It solves the problem that the conventional principal component analysis (PCA) algorithm cannot compensate the common but intricate higher order cross-term aberrations, such as astigmatism and coma. Moreover, the dPCA strategy proposed here is not only suitable for aberration compensation but also applicable for other cases where there exist cross-terms that cannot be analyzed with the PCA algorithm.”

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Publication: Journal of Biomedical Optics
Issue/Year: Journal of Biomedical Optics, Volume 26; Number 04; 2021
DOI: 10.1117/1.jbo.26.4.046501