Optics express最新文献

{"title":"Spatially resolved system-level calibration for high-fidelity complex-amplitude modulation using a phase-only spatial light modulator.","authors":"Hwihyeong Lee, Hee Kyung Ahn","doi":"10.1364/OE.611631","DOIUrl":"https://doi.org/10.1364/OE.611631","url":null,"abstract":"<p><p>We demonstrate a spatially resolved system-level calibration method for high-fidelity complex-amplitude modulation using sequential modulation on a phase-only spatial light modulator (SLM). The spatially varying intensity response of the first SLM region was measured and locally fitted to determine the gray-level pattern required to reproduce a target intensity. The phase distribution was also measured using off-axis interferometry and compensated by the second SLM region. The method therefore compensates for the nonuniform incident-beam profile, the spatially varying nonlinear SLM response, and optical-system alignment errors. Once calibrated, the system can reconstruct various target complex fields without additional calibration. Experimental reconstructions of a diverse range of patterns, including structured beam modes, consistently demonstrated high complex-field fidelity.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"34 20","pages":"38224-38239"},"PeriodicalIF":3.4,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149113243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Speckle-based cryptosystem with physically associated authentication and task-dedicated model matching.","authors":"Hanlu Zhang, Lexin Yang, Menghao Jia, Chengbin Wang, Bijun Xu, Xiaogang Wang","doi":"10.1364/OE.613813","DOIUrl":"https://doi.org/10.1364/OE.613813","url":null,"abstract":"<p><p>Existing deep-learning-enabled optical scattering encryption schemes lack effective task-level access control, preventing independent multi-task encryption and decryption. Furthermore, these schemes typically treat the trained single neural network as a global decryption key, introducing critical security vulnerabilities once the model is leaked. To achieve secure multi-task optical scattering encryption and reliable task-model matching, we propose a dual-channel scheme integrating physical marker authentication and a residual-network matching module. Task-specific physical signatures are created by the spatial positions of scattering media and dedicated marker images, while complementary binary matrices serve as digital keys, establishing a hybrid physical-digital access control system. After that, the optical setup generates a marker speckle and an interference-fused speckle carrying both plaintext and marker information; the final ciphertext is constructed by extracting pixels from the corresponding speckle pairs using customized digital keys. Decryption follows two-level verification: physical authentication using the correct binary matrix, followed by activation of the corresponding task-specific residual network for high-quality reconstruction. Experiments demonstrate reliable task-model matching across multiple independent task groups, robust security against key leakage and unauthorized decryption, and effective resistance to cross-verification attacks. This work establishes, what is believed to be, a new paradigm with strengthened physical security for multi-task optical scattering encryption.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"34 20","pages":"37492-37503"},"PeriodicalIF":3.4,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149113262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Subsampling strategies for compressive Hadamard single-pixel imaging.","authors":"C Thomas, N Ducros, J E Cohen, L Jacques, M Georges","doi":"10.1364/OE.608747","DOIUrl":"https://doi.org/10.1364/OE.608747","url":null,"abstract":"<p><p>Single-pixel imaging (SPI) based on Hadamard multiplexing enables efficient image acquisition with a reduced number of measurements, but its performance critically depends on the choice of subsampling strategy. In this work, we conduct a comprehensive evaluation of subsampling strategies for compressive Hadamard SPI, aiming to identify the method that selects the best-suited subset of Hadamard basis vectors. Natural images are known to contain most of their information in low spatial frequencies. Hence, the motivation for subsampling low-sequency patterns first, where sequency is the Hadamard analog of spatial frequency and corresponds to the number of sign changes in a Hadamard pattern, is intuitive but lacks theoretical grounding. This motivates the evaluation of multiple strategies which combine known subsampling schemes-deterministic, variable density sampling, and multilevel density sampling-with several reorderings of the Hadamard basis elements. These follow specific metrics defined on the Hadamard basis, including sequency, total variation, cake-cutting, and to our knowledge a novel data-driven variance-based ordering. In addition, spread spectrum and scrambled Hadamard approaches, relying on a randomization of the Hadamard basis, are considered. The performance of these strategies is assessed across different sampling ratios, Gaussian noise levels, and reconstruction methods, including pseudoinverse, ISTA, and a deep-learning-based approach (PinvNet), both on simulations and on an actual SPI setup. Results on a common, large dataset of images (BSDS500) indicate that deterministic selection of informative Hadamard patterns consistently outperforms probabilistic and randomized compressive sensing strategies. The proposed variance-based ordering achieves state-of-the-art performance for linear and sparsity-based reconstructions, while sequency ordering remains competitive for deep-learning-based reconstruction. These findings highlight the importance of selecting the most informative Hadamard patterns and open the way to data-driven approaches to assess their information content.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"34 20","pages":"38586-38602"},"PeriodicalIF":3.4,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149113282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Direct observation of bistability and resonance evolution in silicon microring resonators using a CW pump-broadband probe technique.","authors":"Liron Gantz, Nikola Nedovic, Ori Eyal, Asaf David, C Thomas Gray","doi":"10.1364/OE.612005","DOIUrl":"https://doi.org/10.1364/OE.612005","url":null,"abstract":"<p><p>Thermal nonlinearities in silicon microring resonators induce resonance shifts and bistability that can impact the stability and performance of optical communication systems. We present a CW pump-broadband probe technique that decouples optical excitation from spectral readout, enabling direct observation of bistability and resonance evolution in low-Q silicon microring resonators under self-heating. Unlike conventional single-laser approaches, where resonance behavior is inferred from transmitted optical power, the proposed method directly measures the resonance spectrum while the cavity is optically excited, providing simultaneous access to the resonance wavelength, linewidth, and resonance depth. Using this approach, we experimentally characterize thermal hysteresis over a wide range of optical powers and evaluate a reduced phenomenological thermal model. Direct observation of the cavity state reveals power-dependent evolution of the resonance linewidth and depth, and incorporating the measured cavity-state evolution significantly improves the predictive accuracy of the reduced model. The resulting model enables reproducible steady-state cavity conditions to be established by balancing optical and electrical heating, achieving equivalent cavity temperature fluctuations of approximately 20 mK (1σ). Building on this capability, we introduce a steady-state operating-space framework that separates the physical cavity state from the external experimental control variables. The proposed method provides a practical framework for quantitative characterization of thermal nonlinearities and nonlinear optical processes in resonant silicon photonic devices.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"34 20","pages":"38425-38444"},"PeriodicalIF":3.4,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149113292","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deep lensless imaging with non-iterative output-constraint satisfaction.","authors":"Shigeru Fujiwara, Hodaka Kawachi, José Reinaldo Cunha Santos A V Silva Neto, Yasushi Yagi, Tomoya Nakamura","doi":"10.1364/OE.608276","DOIUrl":"https://doi.org/10.1364/OE.608276","url":null,"abstract":"<p><p>Deep learning enables high-quality single-pass reconstruction in computational lensless imaging, but its outputs generally do not satisfy the physical observation model <b>y</b> = <b>A</b><b>x</b>. Existing methods that enforce this constraint, such as iterative optimization and diffusion-based approaches, require repeated computation at inference, limiting their applicability in time-sensitive settings. We propose the output-constraint module (OCM), a lightweight add-on that projects the output of any deep learning reconstruction model onto the measurement-consistent subspace without iterative computation. The projection is derived analytically via Lagrange multipliers, yielding a closed-form expression that requires only matrix-vector products at inference. Applied to lensless image reconstruction, OCM reduces the data-consistency loss (the residual of the observation model) by approximately 3 × over unconstrained deep learning and achieves the best reconstruction quality among measurement-consistent single-pass methods, with inference approximately 9 × faster than iterative optimization (ADMM, 100 iterations). Our analysis indicates that the remaining gap in similarity to the paired lensed-camera images between data-driven and measurement-consistent methods largely reflects the mapping between the two camera domains that data-driven models learn implicitly, rather than a loss of scene information.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"34 20","pages":"37137-37151"},"PeriodicalIF":3.4,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149113302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Differentiable optimization of Fourier-plane phase mask for high-fidelity phase-only holography.","authors":"Jianglian Wang, Yuuki Tokunaga, Atsushi Okamoto","doi":"10.1364/OE.611499","DOIUrl":"https://doi.org/10.1364/OE.611499","url":null,"abstract":"<p><p>Phase-only hologram (POH) generation remains a fundamental challenge in holographic displays because of the inherent difficulty in encoding complex amplitudes using phase-only modulation. Existing methods often suffer from the speckle noise introduced by random phase modulation, high computational costs, or reduced spatial resolution caused by zero padding. In this study, we propose a differentiable Fourier-plane random phase mask (RPM) learning framework for high-fidelity POH generation. The Fourier-plane RPM was parameterized as a learnable phase modulation element and optimized within an end-to-end differentiable encoding-reconstruction model. By directly learning the RPM distribution under the phase-only constraint, the proposed method enables accurate holographic reconstruction without zero padding while requiring only a few optimization iterations. Furthermore, a low-resolution parameterization strategy and a multi-sample optimization scheme were introduced to improve generalization and prevent image-specific overfitting. Consequently, the learned RPM exhibited globally stationary statistical properties and could be reused for different target images. Numerical simulations and optical experiments demonstrate that the proposed method enables high-fidelity holographic reconstruction without zero padding while maintaining robust performance under practical optical conditions. The proposed method provides a new route for an efficient and generalizable framework for POH generation in holographic display applications.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"34 20","pages":"38021-38041"},"PeriodicalIF":3.4,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149113305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Image classification using spectral features from a Kerr comb photonic reservoir computer.","authors":"Negar Shaabani Shishavan, Egor Manuylovich, Morteza Kamalian-Kopae, Auro M Perego","doi":"10.1364/OE.604117","DOIUrl":"https://doi.org/10.1364/OE.604117","url":null,"abstract":"<p><p>In this work, we present a photonic classification architecture based on a Kerr microresonator operating as a nonlinear reservoir. The system exploits chaotic optical frequency comb formation in a high-<i>Q</i> microresonator to transform time-encoded input signals into high-dimensional spectral representations. Using the QR-compressed MNIST handwritten digit dataset, we numerically demonstrate that the proposed architecture improves classification accuracy from 71.67% to 83.88% compared with a purely linear baseline, even when only a small subset of input features is used. We further analyze the influence of key resonator parameters on classification performance. These results highlight the potential of nonlinear microresonator-based frequency comb reservoirs as compact photonic processors for machine-learning tasks with low footprint and simple readout.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"34 20","pages":"37924-37941"},"PeriodicalIF":3.4,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149113346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Long-wave infrared detection using spintronic Poisson bolometer arrays.","authors":"Utkarsh Singh, Leif Bauer, Angshuman Deka, Mohamed Mousa, Daien He, Sakshi Gupta, Bhagwati Prasad, Zubin Jacob","doi":"10.1364/OE.606576","DOIUrl":"https://doi.org/10.1364/OE.606576","url":null,"abstract":"<p><p>The use of probabilistic spintronic devices for infrared radiation detection has introduced a shift in the approach to thermal imaging. The integration of probabilistic magnetic tunnel junctions with infrared plasmonic nano-antennas yields digital-mode infrared sensors at room temperature. Here, we present a scalable approach towards multi-pixel plasmonic-spintronic bolometer array fabrication and readout. We fabricate proof-of-concept 2x2 row-column multiplexed probabilistic plasmonic-spintronic arrays and show their response to long-wave infrared radiation (8-14 μm) with high readout speeds (10⁴-10⁶ counts per second). These spintronic, ultrafast, nanoscale (SUN) bolometers can enable high-pixel density CMOS compatible infrared detection platforms. Our work provides a broadband (9 kHz to 3 GHz) readout platform for future digital probabilistic detector applications. Furthermore, our approach addresses a key challenge associated with scaling infrared pixel sizes that can drive progress towards high pixel density detector arrays for infrared sensing and microscopy applications.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"34 20","pages":"37504-37512"},"PeriodicalIF":3.4,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149113388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"BER analysis and enhanced SIC for photon-counting NOMA in photon-limited OWC.","authors":"Weifeng Mou, Huatao Zhu, Xiaoyu Zhao, Chen Wang, Xin Zhang","doi":"10.1364/OE.607987","DOIUrl":"https://doi.org/10.1364/OE.607987","url":null,"abstract":"<p><p>Optical wireless communication (OWC) has emerged as a promising complementary technology to radio frequency systems. Particularly, under photon-limited channel conditions, despite the advantages of single-photon avalanche diodes (SPADs), their performance is limited by dead time and lack of photon-number resolution (PNR), which degrade signal detection in multi-user non-orthogonal multiple access (NOMA) systems. In this paper, we propose what is believed to be a novel posterior-probability-based adjusted threshold-successive interference cancellation (AT-SIC) algorithm to mitigate error propagation and multi-user interference in practical SPAD-based NOMA systems. We develop a comprehensive mathematical framework that incorporates dead time and the lack of PNR effects to derive exact closed-form bit error rate (BER) expressions for both downlink and uplink NOMA over photon-counting channels. The proposed AT-SIC algorithm achieves near-optimal performance with significantly reduced computational complexity. The numerical results validate the accuracy of the analytical model and demonstrate the effectiveness of the proposed method under various channel and power allocation conditions. This study offers a valuable tool for the design and optimization of photon-counting NOMA systems.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"34 20","pages":"38110-38126"},"PeriodicalIF":3.4,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149112169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tunable particle trapping based on a polarization-sensitive transverse bifocal metalens.","authors":"De Jun Liu, Hao Chen Geng, Haoyuan Zhang, Cheng Bo Du, Huiping Tian","doi":"10.1364/OE.595637","DOIUrl":"https://doi.org/10.1364/OE.595637","url":null,"abstract":"<p><p>In this work, we design a polarization-sensitive transverse bifocal metalens whose phase modulation is governed by a hybrid mechanism combining Pancharatnam-Berry (PB) phase and propagation phase. Under linearly or elliptically polarized illumination, the metalens generates two different focal spots along the <i>x</i>-axis. However, for left- or right-circularly polarized (LCP/RCP) light, only a single focal spot is formed on one side. We further investigate the optical trapping performance of the proposed metalens under different polarization states using finite-difference time-domain (FDTD) numerical simulations. The numerical results show that, under linearly and elliptically polarized illumination, simultaneous trapping of particles at the two focal positions can be achieved. By tuning the ellipticity of the incident light, the relative intensity of the two trapping sites can be flexibly controlled. In addition, by switching between LCP and RCP light, the trapped particles can be controllably transferred between the two focal points. Then we analyze the influence of particle size on the transfer performance. Simulation results indicate that for 1000 polystyrene (PS) particles with a radius of 100 nm, the transfer rate of 92.1% is achieved within 0.4 ms after switching the polarization state of the incident light. Finally, we compared the manipulation performance of this metalens on PS particles of different sizes. The results showed that the speed of particle transfer is directly proportional to particle size. This study provides more flexibility and tunability for optical trapping, while presenting new alternatives for particle manipulation and integrated photonic systems based on metalenses operating in the near-infrared regime.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"34 20","pages":"36737-36748"},"PeriodicalIF":3.4,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149112192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}