A mysterious, long-pursued structure of a nanocluster-nanocrystal transition-sized nanoparticle is unraveled.

In the conventional weighted Gerchberg-Saxton (GS) algorithm, the feedback is used to accelerate the convergence. However, it will lead to the iteration divergence. To solve this issue, an adaptive weighted GS algorithm is proposed in this paper. By replacing the conventional feedback with our designed feedback, the convergence can be ensured in the proposed method. Compared with the traditional GS iteration method, the proposed method improves the peak signal-noise ratio of the reconstructed image with 4.8 dB on average. Moreover, an approximate quadratic phase is proposed to suppress the artifacts in optical reconstruction. Therefore, a high-quality image can be reconstructed without the artifacts in our designed Argument Reality device. Both numerical simulations and optical experiments have validated the effectiveness of the proposed method.

The double phase method is an efficient way to generate phase-only holograms with high reconstruction quality due to no addition of a random phase. However, it cannot directly encode the Fourier spectrum because of the limited gray modulation range of spatial light modulator and quantization error. This shortage restricts the application of the double phase in the phase-only Fourier hologram, and this issue is never discussed and solved as far as we know. To solve this issue, we propose a method to generate phase-only Fourier hologram by analyzing quantization error and adding a proper quadratic phase. The proposed method overcomes the shortage and outperforms the noniterative bidirectional error diffusion method in reconstruction quality and calculation speed with 8.9 dB higher and 33 times faster on average, respectively.

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Lattice tuning at the ≈1 nm scale is fascinating and challenging; for instance, lattice compression at such a minuscule scale has not been observed. The lattice compression might also bring about some unusual properties, which waits to be verified. Through ligand induction, we herein achieve the lattice compression in a ≈1 nm gold nanocluster for the first time, as detected by the single‐crystal X‐ray crystallography. In a freshly synthesized Au52(CHT)28 (CHT=S‐c−C6H11) nanocluster, the lattice distance of the (110) facet is found to be compressed from 4.51 to 3.58 Å at the near end. However, the lattice distances of the (111) and (100) facets show no change in different positions. The lattice‐compressed nanocluster exhibits superior electrocatalytic activity for the CO2 reduction reaction (CO2RR) compared to that exhibited by the same‐sized Au52(TBBT)32 (TBBT=4‐tert‐butyl‐benzenethiolate) nanocluster and larger Au nanocrystals without lattice variation, indicating that lattice tuning is an efficient method for tailoring the properties of metal nanoclusters. Further theoretical calculations explain the high CO2RR performance of the lattice‐compressed Au52(CHT)28 and provide a correlation between its structure and catalytic activity.

The crosstalk noise produced in the multiplexing technology of curved computer-generated holograms has caused great damage to reconstructed objects. In order to solve this problem, we propose a method to realize three-dimensional object reconstruction with low crosstalk noise impact. By multiplexing the spherical holograms in the horizontal and vertical directions, the complex amplitudes of the multiple spherical holograms with different curvatures are added to form a composed hologram. The generated hologram records many unrelated scenes of the object. According to the different angles used to generate the hologram, the original object under different viewpoints can be rebuilt, and the multiview multiplexing and reconstruction of three-dimensional objects can be realized. Simulation and optical experiments verify the feasibility of this method.

A holographic three-dimensional (3D) display is a recognized and ideal 3D display technology. In the field of holographic research, cylindrical holography with the merit of 360° field of view (FOV) has recently become a hot issue, as it naturally solves the problem of limited FOV in planar holography. The recently proposed approximate phase compensation (APC) method successfully obtains larger FOV and fast generation of segment cylindrical hologram (SCH) in the visible light band. However, the FOV of SCH remains limited due to its intrinsic limitations, and, to our best knowledge, the issue has not been effectively addressed. In this paper, the restricted conditions are first analyzed for the generation of SCH by the APC method. Then, an FOV expansion method is proposed for realizing a large FOV holographic display by gapless splicing of multi-SCH. The proposed method can successfully obtain larger FOV cylindrical holograms and effectively eliminate the splicing gaps; its effectiveness is verified by the results of numerical simulation and optical experiments. Therefore, the proposed method can effectively solve the FOV limitation problem of the APC method for the generation of SCH in the visible band, realize a large FOV 3D display, and provide a useful reference for holographic 3D display.

As a method of near-field diffraction in the condition of the paraxial approximation, the Fresnel convolution (FR-CV) method is widely used in hologram generation and other applications. However, it is applicable to near-field diffraction, and the quality of holographic reconstruction degrades seriously with the increase of diffraction distance. Moreover, its hologram generation speed is limited due to the use of three fast Fourier transforms in the convolution operation. Nevertheless, there are also many application scenarios that need longer distance diffraction. To achieve a holographic display in broadened distance with high generation speed and reconstruction quality, an optical computational Fresnel convolution method is proposed in this paper. Since an optical Fourier lens is used to perform optical calculations for Fourier transforms in our proposed method, the hologram generation speed of the proposed method is approximately 8 times faster than that of the FR-CV method. Moreover, the reconstructed image with our proposed method can be successfully and clearly displayed at both short and longer diffraction distance by changing focal lengths of the Fourier lens. The effectiveness and superiority of the proposed method have been validated by both numerical simulations and optical experiments.