Advanced Photonics
Xiao-Cong (Larry) Yuan, Anatoly Zayats

The image depicts a schematic of the integrated-resonant metadevice composed of various multifunctional integrated-resonant units, as well as their subsequent applications, including polarization detection, orbital angular momentum generation, metaholography, nonlinear generation, and so on.

Luca Pezzè

The article comments on a recent advance in optical quantum metrology.

Mar. 21, 2023
  • Vol. 5 Issue 2 020501 (2023)
  • Huanhao Li, Zhipeng Yu, Tianting Zhong, Shengfu Cheng, and Puxiang Lai

    Controllable optical propagation, such as forming diffraction-limited optical focusing, beyond the diffusion limit in biological tissue or tissue-like scattering media, has been desired for long yet considered challenging. In the past two decades, optical wavefront shaping (WFS) has been proposed and has progressed, demonstrating its remarkable potential. That said, inherent tradeoffs still exist among optimization speed, control degree of freedom, and energy gain, which has hindered wide applications of the technology. Most recently, an analogue optical phase conjugation system was developed, equipped with stimulated emission light amplification that effectively achieves the least tradeoff ever, yielding high-gain and high-speed performance of optical focusing through dynamic thick media.

    Apr. 20, 2023
  • Vol. 5 Issue 2 020502 (2023)
  • Riccardo Degl’Innocenti

    Dynamic control of terahertz (THz) waves is a significant area of intense research. For modulating terahertz (THz) waves, metamaterials have emerged as a promising solution. This article comments on an innovative approach that was recently published.

    Apr. 26, 2023
  • Vol. 5 Issue 2 020503 (2023)
  • Jin Yao, Rong Lin, Mu Ku Chen, and Din Ping Tsai

    Integrated-resonant units (IRUs), associating various meta-atoms, resonant modes, and functionalities into one supercell, have been promising candidates for tailoring composite and multifunctional electromagnetic responses with additional degrees of freedom. Integrated-resonant metadevices can overcome many bottlenecks in conventional optical devices, such as broadband achromatism, efficiency enhancement, response selectivity, and continuous tunability, offering great potential for performant and versatile application scenarios. We focus on the recent progress of integrated-resonant metadevices. Starting from the design principle of IRUs, a variety of IRU-based characteristics and subsequent practical applications, including achromatic imaging, light-field sensing, polarization detection, orbital angular momentum generation, metaholography, nanoprinting, color routing, and nonlinear generation, are introduced. Existing challenges in this field and opinions on future research directions are also provided.

    Feb. 22, 2023
  • Vol. 5 Issue 2 024001 (2023)
  • Mingxue Deng, Xingzhong Cao, Yangmin Tang, Zhenzhen Zhou, Lijia Liu, Xiaofeng Liu, Peng Zhang, Lo-Yueh Chang, Hao Ruan, Xinjun Guo, Jiacheng Wang, and Qian Liu

    Luminescent materials often suffer from thermal quenching (TQ), limiting the continuation of their applications under high temperatures up to 473 K. The formation of defect levels could suppress TQ, but rational synthesis and deep understanding of multiple defects-regulated luminescent materials working in such a wide temperature range still remain challenging. Here, we prepare a negative thermal quenching (NTQ) phosphor LiTaO3 : Tb3 + by introducing gradient defects VTa5-, TbLi2+, and ( VTaTbLi)3 - as identified by advanced experimental and theoretical studies. Its photoluminescence significantly becomes intense with rising temperatures and then slowly increases at 373 to 473 K. The mechanism studies reveal that gradient defects with varied trapping depths could act as energy buffer layers to effectively capture the carriers. Under thermal disturbance, the stored carriers could successively migrate to the activators in consecutive and wide temperature zones, compensating for TQ to enhance luminescence emission. This study initiates the synthesis of multi-defect NTQ phosphors for temperature-dependent applications.

    Feb. 14, 2023
  • Vol. 5 Issue 2 026001 (2023)
  • Wenhe Jia, Chenxin Gao, Yongmin Zhao, Liu Li, Shun Wen, Shuai Wang, Chengying Bao, Chunping Jiang, Changxi Yang, and Yuanmu Yang

    Optical metasurfaces are endowed with unparallel flexibility to manipulate the light field with a subwavelength spatial resolution. Coupling metasurfaces to materials with strong optical nonlinearity may allow ultrafast spatiotemporal light field modulation. However, most metasurfaces demonstrated thus far are linear devices. Here, we experimentally demonstrate simultaneous spatiotemporal laser mode control using a single-layer plasmonic metasurface strongly coupled to an epsilon-near-zero (ENZ) material within a fiber laser cavity. While the geometric phase of the metasurface is utilized to convert the laser’s transverse mode from a Gaussian beam to a vortex beam carrying orbital angular momentum, the giant nonlinear saturable absorption of the ENZ material enables pulsed laser generation via the Q-switching process. The direct integration of a spatiotemporal metasurface in a laser cavity may pave the way for the development of miniaturized laser sources with tailored spatial and temporal profiles, which can be useful for numerous applications, such as superresolution imaging, high-density optical storage, and three-dimensional laser lithography.

    Feb. 22, 2023
  • Vol. 5 Issue 2 026002 (2023)
  • Yilin He, Yunhua Yao, Dalong Qi, Yu He, Zhengqi Huang, Pengpeng Ding, Chengzhi Jin, Chonglei Zhang, Lianzhong Deng, Kebin Shi, Zhenrong Sun, Xiaocong Yuan, and Shian Zhang

    Various super-resolution microscopy techniques have been presented to explore fine structures of biological specimens. However, the super-resolution capability is often achieved at the expense of reducing imaging speed by either point scanning or multiframe computation. The contradiction between spatial resolution and imaging speed seriously hampers the observation of high-speed dynamics of fine structures. To overcome this contradiction, here we propose and demonstrate a temporal compressive super-resolution microscopy (TCSRM) technique. This technique is to merge an enhanced temporal compressive microscopy and a deep-learning-based super-resolution image reconstruction, where the enhanced temporal compressive microscopy is utilized to improve the imaging speed, and the deep-learning-based super-resolution image reconstruction is used to realize the resolution enhancement. The high-speed super-resolution imaging ability of TCSRM with a frame rate of 1200 frames per second (fps) and spatial resolution of 100 nm is experimentally demonstrated by capturing the flowing fluorescent beads in microfluidic chip. Given the outstanding imaging performance with high-speed super-resolution, TCSRM provides a desired tool for the studies of high-speed dynamical behaviors in fine structures, especially in the biomedical field.

    Mar. 09, 2023
  • Vol. 5 Issue 2 026003 (2023)
  • Minwoo Jung, and Gennady Shvets

    On-demand modification of the electronic band structures of high-mobility two-dimensional (2D) materials is of great interest for various applications that require rapid tuning of electrical and optical responses of solid-state devices. Although electrically tunable superlattice (SL) potentials have been proposed for band structure engineering of the Dirac electrons in graphene, the ultimate goal of engineering emergent quasiparticle excitations that can hybridize with light has not been achieved. We show that an extreme modulation of one-dimensional (1D) SL potentials in monolayer graphene produces ladder-like electronic energy levels near the Fermi surface, resulting in optical conductivity dominated by intersubband transitions (ISBTs). A specific and experimentally realizable platform comprising hBN-encapsulated graphene on top of a 1D periodic metagate and a second unpatterned gate is shown to produce strongly modulated electrostatic potentials. We find that Dirac electrons with large momenta perpendicular to the modulation direction are waveguided via total internal reflections off the electrostatic potential, resulting in flat subbands with nearly equispaced energy levels. The predicted ultrastrong coupling of surface plasmons to electrically controlled ISBTs is responsible for emergent polaritonic quasiparticles that can be optically probed. Our study opens an avenue for exploring emergent polaritons in 2D materials with gate-tunable electronic band structures.

    Mar. 30, 2023
  • Vol. 5 Issue 2 026004 (2023)
  • Haoyang Zhou, Sheng Zhang, Shunjia Wang, Yao Yao, Qingnan Cai, Jing Lin, Xiaoying Zheng, Zhuo Wang, Zhensheng Tao, Qiong He, and Lei Zhou

    Dynamically controlling terahertz (THz) waves with an ultracompact device is highly desired, but previously realized tunable devices are bulky in size and/or exhibit limited light-tuning functionalities. Here, we experimentally demonstrate dynamic modulation on THz waves with a dielectric metasurface in mode-selective or mode-unselective manners through pumping the system at different optical wavelengths. Quasi-normal-mode theory reveals that the physics is governed by the spatial overlap between wave functions of resonant modes and regions inside resonators perturbed by pump laser excitation at different wavelengths. We further design/fabricate a dielectric metasurface and experimentally demonstrate that it can dynamically control the polarization state of incident THz waves, dictated by the strength and wavelength of the pumping light. We finally numerically demonstrate pump wavelength-controlled optical information encryption based on a carefully designed dielectric metasurface. Our studies reveal that pump light wavelength can be a new external knob to dynamically control THz waves, which may inspire many tunable metadevices with diversified functionalities.

    Apr. 08, 2023
  • Vol. 5 Issue 2 026005 (2023)
  • Yingxuan Chen, Qiqi Zhu, Xutong Wang, Yanbo Lou, Shengshuai Liu, and Jietai Jing

    Quantum state sharing, an important protocol in quantum information, can enable secure state distribution and reconstruction when part of the information is lost. In (k, n) threshold quantum state sharing, the secret state is encoded into n shares and then distributed to n players. The secret state can be reconstructed by any k players (k > n / 2), while the rest of the players get nothing. In the continuous variable regime, the implementation of quantum state sharing needs the feedforward technique, which involves optic-electro and electro-optic conversions. These conversions limit the bandwidth of the quantum state sharing. Here, to avoid the optic-electro and electro-optic conversions, we experimentally demonstrate (2, 3) threshold deterministic all-optical quantum state sharing. A low-noise phase-insensitive amplifier based on the four-wave mixing process is utilized to replace the feedforward technique. We experimentally demonstrate that any two of three players can cooperate to implement the reconstruction of the secret state, while the rest of the players cannot get any information. Our results provide an all-optical platform to implement arbitrary (k, n) threshold deterministic all-optical quantum state sharing and pave the way to construct the all-optical broadband quantum network.

    Apr. 12, 2023
  • Vol. 5 Issue 2 026006 (2023)
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