Applied optics最新文献_第5页

Flexible synthesis of complex microwave waveforms assisted by time-domain operations. 时域运算辅助下复杂微波波形的柔性合成。

Applied optics Pub Date : 2025-09-10 DOI: 10.1364/AO.571720

Xiaohong Lan, Yang Jiang, Jing Xu, Jinjian Feng, Yunkun Luo, Qianyou Long

引用次数: 0

Design method of an off-axis reflective aperture-divided optical system. 离轴反射分孔径光学系统的设计方法。

Applied optics Pub Date : 2025-09-10 DOI: 10.1364/AO.567366

Jie Chen, Liwei Zhu, Tong Yang, Lei Yang, Hongbo Xie

{"title":"Design method of an off-axis reflective aperture-divided optical system.","authors":"Jie Chen, Liwei Zhu, Tong Yang, Lei Yang, Hongbo Xie","doi":"10.1364/AO.567366","DOIUrl":"https://doi.org/10.1364/AO.567366","url":null,"abstract":"The aperture-divided optical system is a significant imaging technique that enables real-time imaging with multiple channels. However, an increasing demand for multi-channel optics presents a substantial challenge for current refractive optical systems with complex structures and a narrow wavelength band. In this paper, we propose a modified design method that combines the strengths of an off-axis reflective system and an aperture-divided optical system to achieve high levels of integration and simplified structure. A design concept of integrated optical layout and local detail optimization is proposed here. We present an analysis showing how local sub-channels' distribution affects the imaging characteristics. An integrated optical system, including a relay group constructed based on the Wassermann-Wolf differential equations and a telescope objective, is built first. The sub-aperture system utilizing distinct local surface regions is gradually established with a close connection. To demonstrate the feasibility and efficiency of the method, an integrated system with an F-number of 1.6 and an entrance pupil of 130 mm is presented with its design strategies. The aperture-divided system illustrates well imaging performance close to the diffraction limit in 3-5 µm at 33 lp/mm. The design strategy we have proposed not only has a broad application to multi-channel imaging but also provides valuable insight into to our knowledge, the new imaging technology.","PeriodicalId":101299,"journal":{"name":"Applied optics","volume":"64 26","pages":"7692-7702"},"PeriodicalIF":0.0,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145115964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Wavelength conversion in the presence of Raman amplification in silicon rib waveguides. 硅肋波导中存在拉曼放大时的波长转换。

Applied optics Pub Date : 2025-09-10 DOI: 10.1364/AO.565309

Somen Adhikary, Atrayee Mishra, Binoy Krishna Ghosh, Dipankar Ghosh, Mousumi Basu

{"title":"Wavelength conversion in the presence of Raman amplification in silicon rib waveguides.","authors":"Somen Adhikary, Atrayee Mishra, Binoy Krishna Ghosh, Dipankar Ghosh, Mousumi Basu","doi":"10.1364/AO.565309","DOIUrl":"https://doi.org/10.1364/AO.565309","url":null,"abstract":"This study presents the wavelength conversion facilitated by the interplay between a co-propagating triangular signal and a Gaussian pump by analyzing the nonlinear phase shift in highly nonlinear silicon-core rib waveguides, marking the first report of its kind, to our knowledge. The interaction between the pump and the signal enables possible amplification driven by cross-phase modulation and stimulated Raman scattering. To substantiate these findings, four waveguides are designed and optimized. Numerical solutions of the coupled amplitude equations result in a Raman gain of ∼18-22dB within a compact size, achieving performance comparable to or exceeding previously reported results. As predicted by the analytical model, spectral intensity doublets emerge, with their wavelength shifts and peak power ratios showing strong dependence on pump power and signal pulse width. Higher pump power causes larger wavelength shifts, while broader signal pulses expedite spectral splitting. The observed red-shift ranges from 65 to 81 nm, while the blue-shift spans 54 to 64 nm. Additionally, TPA and FCA play a crucial role in shaping the spectral doublet, particularly in highly nonlinear silicon waveguides. This work represents the first systematic exploration of wavelength conversion through pump-signal interaction in silicon rib waveguides, incorporating carrier lifetime effects and offering valuable insights into controlling spectral doublet generation for integrated photonic applications.","PeriodicalId":101299,"journal":{"name":"Applied optics","volume":"64 26","pages":"7713-7723"},"PeriodicalIF":0.0,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145115988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

GLAD-grown TiO₂/SnO₂ nanowire heterostructure for enhanced fast-switching photodetection. 用于增强快速开关光检测的纳米线异质结构。

Applied optics Pub Date : 2025-09-10 DOI: 10.1364/AO.570442

Rajib Kumar Nanda, Mitra Barun Sarkar

{"title":"GLAD-grown TiO2/SnO2 nanowire heterostructure for enhanced fast-switching photodetection.","authors":"Rajib Kumar Nanda, Mitra Barun Sarkar","doi":"10.1364/AO.570442","DOIUrl":"https://doi.org/10.1364/AO.570442","url":null,"abstract":"This study investigates a fast-switching photodetector based on heterostructure TiO2/SnO2 nanowire (NW), synthesized by using the GLAD-assisted e-beam evaporation technique. For performance comparison, a heterostructure TiO2/SnO2 thin-film (TF) device was also fabricated. Both the NW and TF heterostructure devices were synthesized on n-type silicon (n-Si) substrates, with gold (Au) as the top contact. Field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), and chemical mapping were employed to conduct morphological and elemental analysis. Characterization of structural properties was accomplished by using X-ray diffraction (XRD). Optical measurements indicated that with two broad visible absorption peaks at 430 nm and 673 nm, the heterostructure TiO2/SnO2 NW sample demonstrated a 2.18-fold enhancement in ultraviolet (UV) absorption and a 1.22-fold enhancement in visible light absorption when compared to its thin-film counterpart. The heterostructure TiO2/SnO2 NW device demonstrated a ∼10-fold photosensitivity enhancement in comparison to the TF device. In addition, it obtained a higher detectivity of 1.193×1010 Jones and a lower noise equivalent power (NEP) of 1.114×10-11W. Fast switching behavior was demonstrated by the current-time (I-T) characteristics, with a rise time of 0.23 s and a fall time of 0.31 s. This confirms the device's potential for high-performance photodetection applications.","PeriodicalId":101299,"journal":{"name":"Applied optics","volume":"64 26","pages":"7848-7855"},"PeriodicalIF":0.0,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145115967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Improvement of image quality by intensity compensation based on temporal multiplexing in a binary phase-only holographic display. 二相纯相位全息显示中基于时间复用的光强补偿改善图像质量。

Applied optics Pub Date : 2025-09-10 DOI: 10.1364/AO.566964

Masaya Hayashi, Yusuke Saita, Takanori Nomura

引用次数: 0

Remote optical methods for vibration monitoring of liquid pipelines. 液体管道振动监测的远程光学方法。

Applied optics Pub Date : 2025-09-10 DOI: 10.1364/AO.573317

V A Nurzai, A V Mostovshchikov, F A Gubarev

{"title":"Remote optical methods for vibration monitoring of liquid pipelines.","authors":"V A Nurzai, A V Mostovshchikov, F A Gubarev","doi":"10.1364/AO.573317","DOIUrl":"https://doi.org/10.1364/AO.573317","url":null,"abstract":"This paper discusses the application of the photomodulation method based on thin holographic films and the laser speckle correlation method for remote optical vibration monitoring of various parts of liquid pumping systems. The paper considers the microstructure of the surface relief of the holographic films used for the photomodulation method and the optical diffraction phenomenon of multi-component light on a refractive cross-grating. The results of monitoring the vibration of the pipeline, pillar, and pump housing of the water pumping system and the pipeline of the technical oil pumping system in various operation modes using the proposed methods are given. The results of experiments aimed at determining the resolution of the oscillation frequency for the photomodulation method are also presented. The achieved maximum difference in the readings of both methods for determining the first harmonic of oscillations was 0.103 Hz. The results obtained by the photomodulation method demonstrated high convergence with similar results obtained by the laser speckle correlation method. A conclusion is made about the possibility of applying the photomodulation method based on thin holographic films as a vibration visualization technique for technological equipment monitoring.","PeriodicalId":101299,"journal":{"name":"Applied optics","volume":"64 26","pages":"7629-7635"},"PeriodicalIF":0.0,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145115824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Switchable-coupling terahertz directional coupler operating at 100 GHz. 工作在100ghz的切换耦合太赫兹定向耦合器。

Applied optics Pub Date : 2025-09-10 DOI: 10.1364/AO.570552

Zhen Zhang, Sen Qiu, Jikun Zhang, Xiongbin Liu, Wu Pan, Yandong Xiao, Xin Chen, Chaoyi Huang, Dandan Wen, Renpu Li, Xiaoyu Ma

{"title":"Switchable-coupling terahertz directional coupler operating at 100 GHz.","authors":"Zhen Zhang, Sen Qiu, Jikun Zhang, Xiongbin Liu, Wu Pan, Yandong Xiao, Xin Chen, Chaoyi Huang, Dandan Wen, Renpu Li, Xiaoyu Ma","doi":"10.1364/AO.570552","DOIUrl":"https://doi.org/10.1364/AO.570552","url":null,"abstract":"In the frequency range of 90-110 GHz, we show a dynamically tunable terahertz directional coupler based on the phase transition properties of vanadium dioxide, allowing for a continuous coupling ration adjustment from -3 to -5dB. To validate the concept experimentally, we created two metallic-dielectric hybrid counterparts that mimic the coupling effects of the VO2 film in both its metallic (shielded branches) and extremely insulating (fully conductive branches) phase states. For -3 and -5dB coupler configurations, respectively, simulation results in the 90-110 GHz range show a coupling degree of -2.1 (0.7 dB imbalance) and -3.8dB (1.0 dB imbalance). The mode coupling dynamics in terahertz directional couplers were investigated through the branch-line waveguide theory, revealing the underlying transmission mechanism. The experimental results for the coupler's S-parameters were in relatively good agreement with the theoretical predictions. The switchable directional coupler proposed in this paper has applications in dynamic terahertz power allocation, terahertz imaging, and electromagnetic stealth.","PeriodicalId":101299,"journal":{"name":"Applied optics","volume":"64 26","pages":"7677-7684"},"PeriodicalIF":0.0,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145115854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Multi-wavelength polarization characteristic constraints for underwater image clarification. 水下图像澄清的多波长偏振特性约束。

Applied optics Pub Date : 2025-09-10 DOI: 10.1364/AO.567237

Yaxin Cai, Jiarui Zhang, JiaQi Tian, Ming Fang

{"title":"Multi-wavelength polarization characteristic constraints for underwater image clarification.","authors":"Yaxin Cai, Jiarui Zhang, JiaQi Tian, Ming Fang","doi":"10.1364/AO.567237","DOIUrl":"https://doi.org/10.1364/AO.567237","url":null,"abstract":"To enhance the recovery performance of underwater image clarification algorithms based on polarization technology in scattering underwater environments, a multi-wavelength polarization constrained underwater image clarification method is proposed. This method takes into account the varying polarization characteristics across different wavelengths. The image is processed by separating it into three RGB color channels (red, green, and blue). Initially, the Stokes vectors of the backscattered light for each of the three channels are individually analyzed. From this analysis, a pair of orthogonally polarized images with identical backscatter intensity is derived for each color channel. Next, the histograms of these orthogonally polarized image pairs are stretched, ensuring that the polarization relationship between them is preserved. Finally, polarization differencing is applied to the orthogonally polarized images in each channel, which are then converted into grayscale images to achieve improved image clarity. The effectiveness of the proposed method has been validated through a series of polarization de-scattering experiments conducted in water with varying turbidity levels. These experiments demonstrate the method's superior performance in image restoration, particularly in scenarios with high polarization characteristics when compared to other similar approaches.","PeriodicalId":101299,"journal":{"name":"Applied optics","volume":"64 26","pages":"7602-7610"},"PeriodicalIF":0.0,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145115889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Performance loss and recovery of virtually imaged phased arrays with imperfect mirror parallelism. 不完全镜像平行度虚像相控阵的性能损失与恢复。

Applied optics Pub Date : 2025-09-10 DOI: 10.1364/AO.570670

Ketana Teav, Hubert Jean-Ruel, Adam M Steinberg

{"title":"Performance loss and recovery of virtually imaged phased arrays with imperfect mirror parallelism.","authors":"Ketana Teav, Hubert Jean-Ruel, Adam M Steinberg","doi":"10.1364/AO.570670","DOIUrl":"https://doi.org/10.1364/AO.570670","url":null,"abstract":"Practical defects in parallel-plate interferometers reduce instrument finesse, compromising spectral resolution, and can distort measured spectral lineshapes. The effect of imperfect mirror parallelism is usually described by a single broadened instrument response function and diminished finesse value. However, such a characterization fails to capture spatial field effects from dispersive interferometers, such as the virtually imaged phased array (VIPA). To explore these effects, a model is developed to compute fringe patterns formed by VIPAs with nonparallel mirrors and imaged along planes at specifiable distances from the paired imaging lens. Following validation against an established VIPA model and standard etalon theory with ideal parallel-plate configurations, the new model is used to examine the effects of mirror nonparallelism. While it captures the general loss of instrument performance in spectral resolution and finesse, it also reveals fringe lineshape distortions and nonuniformity of resolution and intensity scaling across the measurement field. Furthermore, when the measurement plane is decoupled from the back focal plane of the lens, there is an evolution of field behavior, and near-ideal instrument performance is recovered within a limited region of the measurement field. Results compare favorably to Zemax simulations and experimental data. This work identifies and characterizes nonideal optical behavior arising from practical defects in mirror parallelism, thereby enabling recognition of measurement artifacts, and imparts remedial measures for selective recovery of instrument finesse.","PeriodicalId":101299,"journal":{"name":"Applied optics","volume":"64 26","pages":"7834-7847"},"PeriodicalIF":0.0,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145115841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Estimation of variable optical feedback coupling factor for self-mixing interferometry by signal-to-image translation. 信像平移自混合干涉中可变光反馈耦合系数的估计。

Applied optics Pub Date : 2025-09-10 DOI: 10.1364/AO.567935

Asra Abid Siddiqui, Wajahat Hussain, Olivier D Bernal, Usman Zabit

{"title":"Estimation of variable optical feedback coupling factor for self-mixing interferometry by signal-to-image translation.","authors":"Asra Abid Siddiqui, Wajahat Hussain, Olivier D Bernal, Usman Zabit","doi":"10.1364/AO.567935","DOIUrl":"https://doi.org/10.1364/AO.567935","url":null,"abstract":"Accurate estimation of the optical feedback coupling factor C is essential for the reliable operation of laser-based self-mixing interferometry (SMI) sensors, particularly in variable feedback conditions. In this work, we present a novel deep learning-based method, to the best of our knowledge, to estimate the time-varying C factor from SMI signals under strong, moderate, and weak feedback conditions. The proposed approach leverages a transformation of one-dimensional (1D) SMI signals into two-dimensional (2D) image representations, allowing convolutional neural networks to extract context-rich features that enhance estimation performance. Unlike traditional image-processing tasks, this method formulates the problem as a signal-to-image translation, tailored for sensor parameter inference. Experimental results demonstrate that this 2D-based approach outperforms state-of-the-art recurrent neural network models, including LSTM and transformer architectures, particularly in terms of robustness to changes in sampling frequency, displacement amplitude, and feedback regime. The methodology is generic and applicable to a wide range of sensor signal analysis tasks. To support reproducibility and practical adoption, we provide a publicly available implementation of our approach.","PeriodicalId":101299,"journal":{"name":"Applied optics","volume":"64 26","pages":"7788-7798"},"PeriodicalIF":0.0,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145115941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0