Advanced metasurfaces: precise modulations of light in space and time domains
Chenxi Zhang, Linyu Cong, Jinhong Zhang, Hongbei Meng, Sirui Peng, Shijin Li, He Zhang, Yikun Wang, Bo Fu, Jiyong Wang, and Min Qiu
Metasurfaces, artificial two-dimensional layered materials with a sub-wavelength thickness, have gained significant interest due to their unparalleled ability to precisely manipulate the amplitude, polarization, phase, and other intrinsic properties of electromagnetic waves. In addition, the development of metasurfaces provides a new idea of “structure instead of material,” through the local enhancement of the optical field and resonance modulation, which can break through the limitations of the material’s intrinsic nonlinear effects, to realize the significant improvement of performance parameters in the sub-ps time domain. This review discusses the design principles, fabrication, and numerical simulation methods of metasurfaces, as well as their modulation characteristics of light in space and time domains. In the applications, the contribution of metasurfaces to optical modulation and imaging in the space domain is summarized, with a focus on their phase and polarization manipulation capabilities. Particularly, we are attentive to the application of metasurfaces in the time domain, probing into the relationship between metasurface structure and nonlinear optical properties, as well as the generation of pulsed lasers via mode-locked and Q-switched techniques. Finally, the developments and challenges of metasurfaces are summarized with an outlook provided to give a comprehensive understanding of metasurfaces and to facilitate their practical applications.Metasurfaces, artificial two-dimensional layered materials with a sub-wavelength thickness, have gained significant interest due to their unparalleled ability to precisely manipulate the amplitude, polarization, phase, and other intrinsic properties of electromagnetic waves. In addition, the development of metasurfaces provides a new idea of “structure instead of material,” through the local enhancement of the optical field and resonance modulation, which can break through the limitations of the material’s intrinsic nonlinear effects, to realize the significant improvement of performance parameters in the sub-ps time domain. This review discusses the design principles, fabrication, and numerical simulation methods of metasurfaces, as well as their modulation characteristics of light in space and time domains. In the applications, the contribution of metasurfaces to optical modulation and imaging in the space domain is summarized, with a focus on their phase and polarization manipulation capabilities. Particularly, we are attentive to the application of metasurfaces in the time domain, probing into the relationship between metasurface structure and nonlinear optical properties, as well as the generation of pulsed lasers via mode-locked and Q-switched techniques. Finally, the developments and challenges of metasurfaces are summarized with an outlook provided to give a comprehensive understanding of metasurfaces and to facilitate their practical applications.
- Dec. 10, 2025
- Advanced Photonics
- Vol. 8, Issue 1, 014003 (2026)
- DOI：10.1117/1.AP.8.1.014003
Physics-informed meta neural representation for high-fidelity, aberration-corrected, sparse-view Fourier ptychographic tomography
Minglu Sun, Fenghe Zhong, Shiqi Mao, Ying Liu, Zihao Zhang, Dongyu Li, Binbing Liu, and Peng Fei
Label-free 3D tomography has attracted growing attention in biological imaging due to its inherent resistance to phototoxicity and concise system configuration. Among existing techniques, Fourier ptychographic tomography (FPT) stands out for high-resolution refractive index (RI) reconstruction from noninterferometric measurements, avoiding coherent noise and phase instability—key limitations of optical diffraction tomography. However, conventional FPT suffers from significant artifacts and high computational demands, especially for multiscattering samples and long-term observation. Here, we introduce physics-informed aberration-corrected meta neural representation (PAMR), an advanced self-supervised framework that integrates neural representation with physics prior, meta-learning optimization, and adaptive aberration correction. Simulations and experiments show that PAMR produces high-fidelity 3D reconstructions with reduced artifacts and strong optical section ability, achieving 137 and 550 nm resolution for lateral and axial, respectively. Moreover, PAMR exhibits superior sparse-view robustness, sustaining high-quality with 75% view reduction. Through the meta-learning strategy, the reconstruction speed of dynamic volumes could be increased by 10 times. Applications include 3D RI imaging of multiscattering C. elegans and long-term 3D observation of HeLa cells, showing detailed organelle structures and interactions. As a generalizable approach combining computational efficiency with physical accuracy, PAMR provides an advanced algorithm for label-free 3D microscopy, with broad applicability across biomedical research.Label-free 3D tomography has attracted growing attention in biological imaging due to its inherent resistance to phototoxicity and concise system configuration. Among existing techniques, Fourier ptychographic tomography (FPT) stands out for high-resolution refractive index (RI) reconstruction from noninterferometric measurements, avoiding coherent noise and phase instability—key limitations of optical diffraction tomography. However, conventional FPT suffers from significant artifacts and high computational demands, especially for multiscattering samples and long-term observation. Here, we introduce physics-informed aberration-corrected meta neural representation (PAMR), an advanced self-supervised framework that integrates neural representation with physics prior, meta-learning optimization, and adaptive aberration correction. Simulations and experiments show that PAMR produces high-fidelity 3D reconstructions with reduced artifacts and strong optical section ability, achieving 137 and 550 nm resolution for lateral and axial, respectively. Moreover, PAMR exhibits superior sparse-view robustness, sustaining high-quality with 75% view reduction. Through the meta-learning strategy, the reconstruction speed of dynamic volumes could be increased by 10 times. Applications include 3D RI imaging of multiscattering C. elegans and long-term 3D observation of HeLa cells, showing detailed organelle structures and interactions. As a generalizable approach combining computational efficiency with physical accuracy, PAMR provides an advanced algorithm for label-free 3D microscopy, with broad applicability across biomedical research.
- Dec. 10, 2025
- Advanced Photonics Nexus
- Vol. 4, Issue 6, 066017 (2025)
- DOI：10.1117/1.APN.4.6.066017
High-power laser drivers and fast neutron sources towards green energy applications
Federico Canova, Itamar Cohen, Leonida Antonio Gizzi, Gerard Mourou, Karoly Osvay, Ales Necas, Vincenzo Romanello, Sidney Galès, Ishay Pomerantz, and Jonathan Wheeler
Accelerator-driven systems (ADSs) may offer a promising technology for energy production and transmutation of nuclear waste. Here we introduce the concept of utilizing high-intensity laser acceleration technology in realizing an ADS, with a focus on the use of thorium fuel in subcritical systems. We explore state-of-the-art laser-driven particle sources for neutron generation by nuclear fusion, spallation or photonuclear reactions and the prospect of reaching the flux of ${10}^{15}$ n/s required to drive a subcritical reactor. We review recent advances in high-power laser amplification and assess their technological readiness in view of integration in an ADS. Finally, we present a risk analysis of a laser-driven ADS in terms of laser and target development, radiation safety and operational stability. Our conclusion highlights the potential of laser-driven ADSs as a transformative approach to nuclear fission energy. With continued research and development, technological hurdles can be overcome to fully realize sustainable, green energy production that can meet global energy demands while addressing safety and environmental concerns.Accelerator-driven systems (ADSs) may offer a promising technology for energy production and transmutation of nuclear waste. Here we introduce the concept of utilizing high-intensity laser acceleration technology in realizing an ADS, with a focus on the use of thorium fuel in subcritical systems. We explore state-of-the-art laser-driven particle sources for neutron generation by nuclear fusion, spallation or photonuclear reactions and the prospect of reaching the flux of ${10}^{15}$ n/s required to drive a subcritical reactor. We review recent advances in high-power laser amplification and assess their technological readiness in view of integration in an ADS. Finally, we present a risk analysis of a laser-driven ADS in terms of laser and target development, radiation safety and operational stability. Our conclusion highlights the potential of laser-driven ADSs as a transformative approach to nuclear fission energy. With continued research and development, technological hurdles can be overcome to fully realize sustainable, green energy production that can meet global energy demands while addressing safety and environmental concerns.
- Dec. 10, 2025
- High Power Laser Science and Engineering
- Vol. 13, Issue 5, 05000e79 (2025)
- DOI：10.1017/hpl.2025.10038
High-energy 2 μ m waveguide laser on a fluoride platform
Ji Eun Bae, Pavel Loiko, Fabian Rotermund, Gurvan Brasse, Alain Braud, Blandine Guichardaz, and Patrice Camy
Chip-scale laser sources capable of delivering high power and energy in the eye-safe 2 μm spectral range are essential for applications in medicine and environmental sensing. We report a remarkable advancement in pulsed 2 μm waveguide laser technology through the integration of high-quality large-mode-area Tm3+-doped fluoride channel waveguides with low-loss, directly deposited single-walled carbon nanotubes on cavity mirrors, serving as efficient saturable absorbers. Comprehensive characterization of these nonlinear mirrors revealed optimized chirality distribution of carbon nanotubes and favorable nonlinear absorption dynamics, enabling efficient passive Q-switching. The proposed configuration achieved a record output power exceeding 1 W and an optical efficiency over 60%—the highest reported for any pulsed, integrated 2 μm coherent light source to date, significantly outperforming silicon-photonics-based systems. Additionally, the device delivered microjoule-level pulse energies at MHz-level high repetition rates, establishing a new milestone in compact, high-performance waveguide laser architectures.Chip-scale laser sources capable of delivering high power and energy in the eye-safe 2 μm spectral range are essential for applications in medicine and environmental sensing. We report a remarkable advancement in pulsed 2 μm waveguide laser technology through the integration of high-quality large-mode-area
- Dec. 08, 2025
- Photonics Research
- Vol. 14, Issue 1, 1 (2026)
- DOI：10.1364/PRJ.567653
Statistical compressive sensing method for Hadamard-based single-pixel microscopy supported by kernel density estimators
H. Tobon-Maya, S. I. Zapata-Valencia, M. Obando, F. Lucka, E. Tajahuerce, and J. Lancis
Hadamard-based single-pixel microscopy (HSPM) is a versatile non-conventional imaging technique where a binary function base is projected over the sample in a microscope setup to recover its information. One HSPM’s main challenge is the need to project numerous patterns to retrieve the image of the object under study. This leads to potential phototoxicity damage and a reduction in temporal resolution. Aiming to reduce the total pattern projection time, this study explores the use of statistical compressive sensing (CS) using the kernel density estimator (KDE) approach to learn the probability distribution of the most relevant Hadamard spectrum (HS) sampling coefficients, based on a large-scale dataset of 50,000 histopathology images. The probability distribution can then be sampled to generate the set of Hadamard patterns to be projected. The proposed KDE-guided CS method is implemented and tested on biological and non-biological samples. An image resolution of 550 lp/mm was recovered at a 25% sampling ratio (SR) using the proposed method, a level not reached by the well-established TV-based approach. Moreover, compared to TV-based sampling, the Michelson contrast increased from 0.09 to 0.17 at a 25% SR and from 0.12 to 0.29 at a 30% SR. These results demonstrate the feasibility of the proposed method for HSPM CS applications.Hadamard-based single-pixel microscopy (HSPM) is a versatile non-conventional imaging technique where a binary function base is projected over the sample in a microscope setup to recover its information. One HSPM’s main challenge is the need to project numerous patterns to retrieve the image of the object under study. This leads to potential phototoxicity damage and a reduction in temporal resolution. Aiming to reduce the total pattern projection time, this study explores the use of statistical compressive sensing (CS) using the kernel density estimator (KDE) approach to learn the probability distribution of the most relevant Hadamard spectrum (HS) sampling coefficients, based on a large-scale dataset of 50,000 histopathology images. The probability distribution can then be sampled to generate the set of Hadamard patterns to be projected. The proposed KDE-guided CS method is implemented and tested on biological and non-biological samples. An image resolution of 550 lp/mm was recovered at a 25% sampling ratio (SR) using the proposed method, a level not reached by the well-established TV-based approach. Moreover, compared to TV-based sampling, the Michelson contrast increased from 0.09 to 0.17 at a 25% SR and from 0.12 to 0.29 at a 30% SR. These results demonstrate the feasibility of the proposed method for HSPM CS applications.
- Dec. 08, 2025
- Advanced Imaging
- Vol. 3, Issue 1, A00002 (2026)
- DOI：10.3788/AI.2026.10001
Solid 226 nm laser pumped by a Nd:YAG laser for two-photon absorption detection of oxygen
Yi Zhang, Shaoyi Wang, Minghao Yu, Zhongqi Feng, and Dacheng Zhang
We present a solid 226 nm deep ultraviolet laser system pumped by a Nd:YAG laser. A diamond Raman laser with a 1485 nm wavelength was generated up to 2.53 mJ pumped by a 9.7 mJ 1064 nm laser, which is the highest pulse energy of a second Stokes diamond Raman laser pumped by a 1064 nm laser as we know. Then, the Raman laser is mixed with the frequency-quadrupled 1064 nm laser to produce the 226 nm laser. The maximum output pulse energy at 226 nm reaches 0.49 mJ. The overall conversion efficiency from 1064 to 226 nm is up to 1.14%, which is significantly higher than conventional optical parametric oscillator technology for the generation of 226 nm laser. The 226 nm laser system has been used in a laser-induced fluorescence (LIF) experiment of oxygen two-photon to demonstrate its potential for LIF measurements.We present a solid 226 nm deep ultraviolet laser system pumped by a Nd:YAG laser. A diamond Raman laser with a 1485 nm wavelength was generated up to 2.53 mJ pumped by a 9.7 mJ 1064 nm laser, which is the highest pulse energy of a second Stokes diamond Raman laser pumped by a 1064 nm laser as we know. Then, the Raman laser is mixed with the frequency-quadrupled 1064 nm laser to produce the 226 nm laser. The maximum output pulse energy at 226 nm reaches 0.49 mJ. The overall conversion efficiency from 1064 to 226 nm is up to 1.14%, which is significantly higher than conventional optical parametric oscillator technology for the generation of 226 nm laser. The 226 nm laser system has been used in a laser-induced fluorescence (LIF) experiment of oxygen two-photon to demonstrate its potential for LIF measurements.
- Dec. 08, 2025
- Advanced Photonics Nexus
- Vol. 5, Issue 1, 016003 (2026)
- DOI：10.1117/1.APN.5.1.016003
High-contrast optical coherence tomography angiography via log-scale inverse static-to-dynamic ratio analysis for weak flow signal
Jinyu Fan, Jiangjie Huang, Ning Tang, Jingye Gu, Lina Xing, Yi He, and Guohua Shi
The conventional optical coherence tomography angiography (OCTA) algorithm is implemented in the linear domain, which may lead to the neglect of weak blood flow information. Logarithmic transformation is widely used in signal analysis to improve the contrast of weak signals. However, decorrelation-based OCTA in the logarithmic domain is also sensitive to the signal-to-noise ratio (SNR) even in high SNR regions, introducing strong flow artifacts that severely reduce the blood vessel contrast. A metric—static-to-dynamic ratio (SDR)—was used to quantify weak flow signals, and a weak flow model among decorrelation, SDR, and SNR was established. Based on this model, we proposed a log-scale inverse SDR-based OCTA method (logiSDR-OCTA), which simultaneously and effectively reduces SNR-induced flow artifacts in static regions and prevents the attenuation of the flow signal in dynamic regions. The in vivo imaging experiments demonstrated that the contrast of the mouse brain logiSDR images was 2.43 times that of linear-scale decorrelation images and 2.71 times that of log-scale subtraction images; the contrast of the human retina logiSDR images was 4.91 times that of linear-scale decorrelation images and 3.56 times that of log-scale subtraction images.The conventional optical coherence tomography angiography (OCTA) algorithm is implemented in the linear domain, which may lead to the neglect of weak blood flow information. Logarithmic transformation is widely used in signal analysis to improve the contrast of weak signals. However, decorrelation-based OCTA in the logarithmic domain is also sensitive to the signal-to-noise ratio (SNR) even in high SNR regions, introducing strong flow artifacts that severely reduce the blood vessel contrast. A metric—static-to-dynamic ratio (SDR)—was used to quantify weak flow signals, and a weak flow model among decorrelation, SDR, and SNR was established. Based on this model, we proposed a log-scale inverse SDR-based OCTA method (logiSDR-OCTA), which simultaneously and effectively reduces SNR-induced flow artifacts in static regions and prevents the attenuation of the flow signal in dynamic regions. The in vivo imaging experiments demonstrated that the contrast of the mouse brain logiSDR images was 2.43 times that of linear-scale decorrelation images and 2.71 times that of log-scale subtraction images; the contrast of the human retina logiSDR images was 4.91 times that of linear-scale decorrelation images and 3.56 times that of log-scale subtraction images.
- Dec. 05, 2025
- Advanced Photonics Nexus
- Vol. 5, Issue 1, 016002 (2026)
- DOI：10.1117/1.APN.5.1.016002
Spiral-galaxies-inspired structured light and optical trapping
Yufeng Sun, Lu Peng, Jiongchao Zeng, Jun Yao, Yidong Liu, Sheng Sun, Wen Xiao, Yuxuan Ren, Huanyang Chen, Jun Hu, and Yuanjie Yang
Spiral galaxies are the most common type of galaxies in the universe, and most spiral galaxies contain a supermassive black hole in their center. However, thus far, the formation of spiral galaxies is still not fully understood, and especially, what determines the number of spiral arms is still an open question as well. Here, inspired by fascinating spiral galaxies, we demonstrate that such a spiral-galaxy-shaped optical field can be generated by interference of a vortex wave and a trumpet wave. Interestingly, we show it is the topological charge of the vortex wave that determines the number of spiral arms in our model. Moreover, we experimentally trap nanoparticles using the structured light and get a spiral-galaxy-like model in a lab. Lastly, we discuss the origin of the trumpet wave through transformation optics and discuss the similarity between our model and spiral galaxies.Spiral galaxies are the most common type of galaxies in the universe, and most spiral galaxies contain a supermassive black hole in their center. However, thus far, the formation of spiral galaxies is still not fully understood, and especially, what determines the number of spiral arms is still an open question as well. Here, inspired by fascinating spiral galaxies, we demonstrate that such a spiral-galaxy-shaped optical field can be generated by interference of a vortex wave and a trumpet wave. Interestingly, we show it is the topological charge of the vortex wave that determines the number of spiral arms in our model. Moreover, we experimentally trap nanoparticles using the structured light and get a spiral-galaxy-like model in a lab. Lastly, we discuss the origin of the trumpet wave through transformation optics and discuss the similarity between our model and spiral galaxies.
- Dec. 03, 2025
- Photonics Research
- Vol. 13, Issue 12, B133 (2025)
- DOI：10.1364/PRJ.575648
Orbital angular momentum beams demultiplexing using a hybrid Fourier phase shift neural network
Jiachi Ye, Tongyao Wu, Abdulaziz Bazammul, Qian Cai, Belal Jahannia, Zibo Hu, Hao Wang, Hamed Dalir, and Elham Heidari
The exponential growth in data traffic has driven significant research into maximizing the capacity of free-space optical (FSO) communication systems. Orbital angular momentum (OAM) multiplexing offers a promising approach by using spatially structured beams with helical wavefronts to achieve higher data transmission rates. However, conventional electronic convolutional-neural-network-based OAM demultiplexing schemes exhibit substantial computational and energy efficiency limitations. In this paper, we introduce a hybrid optical-electronic Fourier phase shift neural network that implements phase-only feature extraction of the input multiplexed OAM beams in the Fourier domain. The proposed hybrid neural network uses phase spatial frequency kernels with the spatial light modulator to perform additive phase modulation of the Fourier-transformed input beams. Experimental results show that the proposed phase shift neural network has 6.5 times faster training time and three orders of magnitude higher energy efficiency compared to the designed conventional all-electronic convolutional neural network with one single convolution layer. The proposed system represents an idea towards energy-efficient, high-throughput optical neural networks for OAM-based FSO communication systems.The exponential growth in data traffic has driven significant research into maximizing the capacity of free-space optical (FSO) communication systems. Orbital angular momentum (OAM) multiplexing offers a promising approach by using spatially structured beams with helical wavefronts to achieve higher data transmission rates. However, conventional electronic convolutional-neural-network-based OAM demultiplexing schemes exhibit substantial computational and energy efficiency limitations. In this paper, we introduce a hybrid optical-electronic Fourier phase shift neural network that implements phase-only feature extraction of the input multiplexed OAM beams in the Fourier domain. The proposed hybrid neural network uses phase spatial frequency kernels with the spatial light modulator to perform additive phase modulation of the Fourier-transformed input beams. Experimental results show that the proposed phase shift neural network has 6.5 times faster training time and three orders of magnitude higher energy efficiency compared to the designed conventional all-electronic convolutional neural network with one single convolution layer. The proposed system represents an idea towards energy-efficient, high-throughput optical neural networks for OAM-based FSO communication systems.
- Dec. 03, 2025
- Photonics Research
- Vol. 13, Issue 12, B120 (2025)
- DOI：10.1364/PRJ.571526
Reflective metasurface connector for high-density and wideband space-division multiplexing
Pengjiu Zhao, Jiangbing Du, Shaoxing Wang, Leyan Fei, Ting Lei, Luping Du, Qunbi Zhuge, and Zuyuan He
In this work, a reflective metasurface connector (RMC) and its application for high-density and wideband space-division multiplexing (SDM) are demonstrated. This device features single facet metasurface fabrication over an SOI platform based on a CMOS compatible process. A minimum fiber-to-fiber insertion loss of 2.9 dB at 1598.24 nm is realized for fan-in-fan-out (FIFO) applications between a single-mode fiber (SMF) array and a multicore fiber (MCF). A device size of only 0.635 mm×0.127 mm×1 mm is obtained for this device, due to the reflective design over high contrast ratio SOI process, which makes this device highly useful for high-density packaging with great potential for low-cost volume production. The single facet design also features a simple packaging advantage with one-step coupling between the RMC and fiber-array unit. The 3 dB bandwidth of the device can reach at least 120 nm, covering S, C, L, and U wavebands. The SDM transmission of single wavelength 4×160 Gb/s is experimentally realized at 1525, 1550, 1600, and 1630 nm wavelengths, indicating an aggregated capacity of 2.56 Tb/s (160 Gb/s×4×4) for four-core MCF transmission.In this work, a reflective metasurface connector (RMC) and its application for high-density and wideband space-division multiplexing (SDM) are demonstrated. This device features single facet metasurface fabrication over an SOI platform based on a CMOS compatible process. A minimum fiber-to-fiber insertion loss of 2.9 dB at 1598.24 nm is realized for fan-in-fan-out (FIFO) applications between a single-mode fiber (SMF) array and a multicore fiber (MCF). A device size of only
- Dec. 03, 2025
- Photonics Research
- Vol. 13, Issue 12, 3522 (2025)
- DOI：10.1364/PRJ.573959
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Superintegrated conformable organic transistors based on a universal microlithographic strategy
Dec. 09, 2025
Journal
Dec. 09, 2025
Theme Issue on Time-Varying Photonics (2025)
Submission Open:10 December 2025; Submission Deadline: 30 April 2026
Theme Issue on Time-Varying Photonics (2025)
Submission Open:10 December 2025; Submission Deadline: 30 April 2026
Special Issue on Advanced Direct Drive Laser Driven Fusion Research and Technology (2025)
Submission Open:1 August 2025; Submission Deadline: 30 November 2025
Editor (s): Dimitri Batani, Sebastien Le Pape, Jianqiang Zhu, Ping Zhu
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