Contents 1 Issue (s), 4 Article (s)

Vol. 3, Iss.3—May.1, 2024 • pp: 036001-036004 Spec. pp:

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Vol. 3, Iss.3-May..1,2024
Split Lohmann computer holography: fast generation of 3D hologram in single-step diffraction calculation
Chenliang Chang, Xian Ding, Di Wang, Zhizhou Ren, Bo Dai, Qi Wang, Songlin Zhuang, and Dawei Zhang
Holographic display stands as a prominent approach for achieving lifelike three-dimensional (3D) reproductions with continuous depth sensation. However, the generation of a computer-generated hologram (CGH) always relies on the repetitive computation of diffraction propagation from point-cloud or multiple depth-sliced planar images, which inevitably leads to an increase in computational complexity, making real-time CGH generation impractical. Here, we report a new CGH generation algorithm capable of rapidly synthesizing a 3D hologram in only one-step backward propagation calculation in a novel split Lohmann lens-based diffraction model. By introducing an extra predesigned virtual digital phase modulation of multifocal split Lohmann lens in such a diffraction model, the generated CGH appears to reconstruct 3D scenes with accurate accommodation abilities across the display contents. Compared with the conventional layer-based method, the computation speed of the proposed method is independent of the quantized layer numbers, and therefore can achieve real-time computation speed with a very dense of depth sampling. Both simulation and experimental results validate the proposed method.
Advanced Photonics Nexus
  • Publication Date: Mar. 28, 2024
  • Vol. 3, Issue 3, 036001 (2024)
Single-wavelength size focusing of ultra-intense ultrashort lasers with rotational hyperbolic mirrors
Zhaoyang Li, Yanqi Liu, Xiaoyang Guo, Yuxin Leng, and Ruxin Li
Compressing all the energy of a laser pulse into a spatiotemporal focal cube edged by the laser center wavelength will realize the highest intensity of an ultra-intense ultrashort laser, which is called the λ3 regime or the λ3 laser. Herein, we introduced a rotational hyperbolic mirror—an important rotational conic section mirror with two foci—that is used as a secondary focusing mirror after a rotational parabolic mirror to reduce the focal spot size from several wavelengths to a single wavelength by significantly increasing the focusing angular aperture. Compared with the rotational ellipsoidal mirror, the first focal spot with a high intensity, as well as some unwanted strong-field effects, is avoided. The optimal focusing condition of this method is presented and the enhanced tight focusing for a femtosecond petawatt laser and the λ3 laser is numerically simulated, which can enhance the focused intensities of ultra-intense ultrashort lasers for laser physics.
Advanced Photonics Nexus
  • Publication Date: Mar. 29, 2024
  • Vol. 3, Issue 3, 036002 (2024)
Integrated coherent beam combining system for orbital-angular-momentum shift-keying-based free-space optical links
Bowang Shu, Yuqiu Zhang, Hongxiang Chang, Shiqing Tang, Jinyong Leng, and Pu Zhou
Orbital-angular-momentum (OAM) multiplexing technology offers a significant dimension to enlarge communication capacity in free-space optical links. The coherent beam combining (CBC) system can simultaneously realize OAM multiplexing and achieve high-power laser output, providing substantial advantages for long-distance communication. Herein, we present an integrated CBC system for free-space optical links based on OAM multiplexing and demultiplexing technologies for the first time, to the best of our knowledge. A method to achieve flexible OAM multiplexing and efficient demultiplexing based on the CBC system is proposed and demonstrated both theoretically and experimentally. The experimental results exhibit a low bit error rate of 0.47% and a high recognition precision of 98.58% throughout the entire data transmission process. By employing such an ingenious strategy, this work holds promising prospects for enriching ultra-long-distance structured light communication in the future.
Advanced Photonics Nexus
  • Publication Date: Apr. 15, 2024
  • Vol. 3, Issue 3, 036003 (2024)
Frequency-dependent selectively oriented edge state topological transport
Jiajun Ma, Chunmei Ouyang, Yuting Yang, Xinyue Qian, Li Niu, Yi Liu, Quan Xu, Yanfeng Li, Zhen Tian, Jianqiang Gu, Jiaguang Han, and Weili Zhang
Valley topological photonic crystals (TPCs), which are robust against local disorders and structural defects, have attracted great research interest, from theoretical verification to technical applications. However, previous works mostly focused on the robustness of topologically protected edge states and little attention was paid to the importance of the photonic bandgaps (PBGs), which hinders the implementation of various multifrequency functional topological photonic devices. Here, by systematically studying the relationship between the degree of symmetry breaking and the working bandwidth of the edge states, we present spoof surface plasmon polariton valley TPCs with broadband edge states and engineered PBGs, where the operation frequency is easy to adjust. Furthermore, by connecting valley TPCs operating at different frequencies, a broadband multifunctional frequency-dependent topological photonic device with selectively directional light transmission is fabricated and experimentally demonstrated, achieving the functions of wavelength division multiplexing and add–drop multiplexing. We provide an effective and insightful method for building multi-frequency topological photonic devices.
Advanced Photonics Nexus
  • Publication Date: Apr. 17, 2024
  • Vol. 3, Issue 3, 036004 (2024)