Optics express最新文献

{"title":"Single-pixel complex-amplitude imaging based on untrained complex-valued convolutional neural network","authors":"Qi-Hang Liang, Zi-Le Zhang, Xu-Kai Wang, Ya-Nan Zhao, Su-Heng Zhang","doi":"10.1364/oe.532417","DOIUrl":"https://doi.org/10.1364/oe.532417","url":null,"abstract":"Single-pixel imaging is advancing rapidly in complex-amplitude imaging. However, reconstructing high-quality images demands significant acquisition and heavy computation, making the entire imaging process time-consuming. Here we propose what we believe to be a novel single-pixel complex-amplitude imaging (SCI) scheme using a complex-valued convolutional neural network for image reconstruction. The proposed sheme does not need to pre-train on any labeled data, and can quickly reconstruct high-quality complex-amplitude images with the randomly initialized network only under the constraints of the physical model. Simulation and experimental results show that the proposed scheme is effective and feasible, and can achieve a good balance between efficiency and quality. We believe that this work provides a new image reconstruction framework for SCI, and paves the way for its practical applications.","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"105 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141869713","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":"Full mission evaluation of EnMAP water leaving reflectance products using three atmospheric correction processors.","authors":"Mariana A Soppa, Maximilian Brell, Sabine Chabrillat, Leonardo M A Alvarado, Peter Gege, Stefan Plattner, Ian Somlai-Schweiger, Thomas Schroeder, François Steinmetz, Daniel Scheffler, Vittorio E Brando, Mariano Bresciani, Claudia Giardino, Simone Colella, Dieter Vansteenwegen, Maximilian Langheinrich, Emiliano Carmona, Martin Bachmann, Miguel Pato, Sebastian Fischer, Astrid Bracher","doi":"10.1364/OE.523813","DOIUrl":"https://doi.org/10.1364/OE.523813","url":null,"abstract":"<p><p>This study presents what we believe is the first extensive assessment of the water reflectance products from the German hyperspectral Environmental Mapping and Analysis Program (EnMAP). We evaluate EnMAP's standard normalized water leaving reflectance [ρ_W]_N over 17 water sites in the first two years of the mission. The EnMAP [ρ_W]_N standard product is generated by a dedicated water atmospheric correction (AC) called the Modular Inversion Program (MIP). The quality of the [ρ_W]_N retrievals was assessed using in situ hyperspectral measurements and Aerosol Robotic Network - Ocean Colour (AERONET-OC) multispectral measurements. The results showed very good agreement between in situ hyperspectral match-ups and EnMAP [ρ_W]_N, with an underestimation of EnMAP of -17.37% (bias, β) and an error (<i>ϵ</i>) of 23.75% at 418 - 797 nm. Two other AC processors were also investigated: the polynomial based algorithm applied to MERIS (Polymer) and the atmospheric correction for OLI lite (Acolite). The intercomparison exercise between the three AC methods applied to EnMAP data using the hyperspectral match-up dataset showed better statistical metrics for MIP (<i>ϵ</i>=23<i>%</i>,<i>β</i>=-17.37<i>%</i>) compared to Polymer (<i>ϵ</i>=42.20<i>%</i>,<i>β</i>=-2.43<i>%</i>) and Acolite (<i>ϵ</i>=97<i>%</i>,<i>β</i>=97<i>%</i>). The superior performance of MIP was further confirmed by the validation results obtained with the multispectral match-up dataset; MIP retrievals show good agreement with in situ measurements at the majority of study sites. Conversely, Polymer and Acolite retrievals tended to overestimate, especially in clearer waters as the Lampedusa study site.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"32 16","pages":"28215-28230"},"PeriodicalIF":3.2,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142624670","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":"Signal enhancement of the gas detection based on quartz-enhanced photothermal spectroscopy technology.","authors":"Jingqi Shi, Jing Zhao, Hengbiao Zhang, Yulong Fu, Lu Qin, Yiyang Zhao, Yiwen Feng, Daming Chen, Zongliang Wang","doi":"10.1364/OE.521916","DOIUrl":"https://doi.org/10.1364/OE.521916","url":null,"abstract":"<p><p>This paper presents an improved gas sensor based on the dual-excitation of quartz-enhanced photothermal spectroscopy (QEPTS) using a single quartz tuning fork (QTF) for signal detection. The silver coating on one side of the QTF was chemically etched to increase the laser power interacted with QTF for QEPTS signal excitation. By etching the silver coating on one side of QTF, the reflection structure between the silver coating of the other side of QTF and the external flat mirror was established. The device uses an absorption gas cell with an optical range length of 3 m, making the laser beam interact with the gas more completely and posing more gas concentration information. Acetylene was selected as the target gas to verify the performance of the sensor. The experimental results show that the signal amplitude with a flat mirror was 1.41 times that without a flat mirror, and 2.47 times that of traditional QEPTS sensor. The system has a minimum detection limit (MDL) of 1.10 ppmv, corresponding to a normalized noise equivalent absorption coefficient (NNEA) of 7.14 × 10^-9cm^-1·W·Hz^-1/2. Allan variance analysis results show that when the integration time is 700 s, the MDL of the system is 0.21 ppmv. The proposed gas sensor can play an important role on detecting trace gas in many fields.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"32 16","pages":"27176-27187"},"PeriodicalIF":3.2,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142625143","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":"Talbot-like pattern evolution in complex structured light from a unitary transformation.","authors":"Zheng-Xiao Cao, Ting-Ting Liu, Bo Zhao, Carmelo Rosales-Guzmán, Jun Liu, Zhi-Han Zhu","doi":"10.1364/OE.530909","DOIUrl":"https://doi.org/10.1364/OE.530909","url":null,"abstract":"<p><p>Astigmatic unitary transformations allow for the adiabatic connections of all feasible states of paraxial Gaussian beams on the same modal sphere, i.e., Hermite-Laguerre-Gaussian (HLG) modes. Here, we present a comprehensive investigation into the unitary modal evolution of complex structured Gaussian beams, comprised of HLG modes from disparate modal spheres, via astigmatic transformation. The non-synchronized higher-order geometric phases in cyclic transformations originate a Talbot-effect-like modal evolution in the superposition state of these HLG modes, resulting in pattern variations and revivals in transformations with specific geodesic loops. Using Ince-Gaussian modes as an illustrative example, we systematically analyze and experimentally corroborate the beamforming mechanism behind the pattern evolution. Our results outline a generic modal conversion theory of structured Gaussian beams via astigmatic unitary transformation, offering a new approach for shaping spatial modal structure. These findings may inspire a wide variety of applications based on structured light.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"32 16","pages":"28025-28034"},"PeriodicalIF":3.2,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142625170","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":"Bayesian approach to coherent combination of single photon beams","authors":"Antoni Mikos-Nuszkiewicz, Jerzy Paczos, Konrad Banaszek, Marcin Jarzyna","doi":"10.1364/oe.530127","DOIUrl":"https://doi.org/10.1364/oe.530127","url":null,"abstract":"We theoretically investigate the performance of a coherent beam combination of two light beams under relative phase fluctuations in the photon starved regime. We apply a first-principles approach using the optimal Bayesian phase correction protocol. We analyze the efficiency of beam combination as a function of the phase fluctuations strength.","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"212 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141869738","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":"Quasi-waveguide amplifiers based on bulk laser gain media in Herriott-type multipass cells.","authors":"Johann Gabriel Meyer, Andrea Zablah, Oleg Pronin","doi":"10.1364/OE.528278","DOIUrl":"https://doi.org/10.1364/OE.528278","url":null,"abstract":"<p><p>We present here what we believe to be a new geometry for laser amplifiers based on bulk gain media. The overlapped seed and pump beams are repetitively refocused into the gain medium with a Herriott-type multipass cell. Similar to a waveguide, this configuration allows for a confined propagation inside the gain medium over much longer lengths than in ordinary single pass bulk amplifiers. Inside the gain medium, the foci appear at separate locations. A proof-of-principle demonstration with Ti:sapphire indicates that this could lead to higher amplification due to a distribution of the thermal load.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"32 15","pages":"25706-25716"},"PeriodicalIF":3.2,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142625591","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":"Spread spectrum for covert communication in ultra-violet communication system.","authors":"Yueke Yang, Yuan Ren, Weijie Liu, Chen Gong, Nuo Huang, Zhengyuan Xu","doi":"10.1364/OE.527516","DOIUrl":"https://doi.org/10.1364/OE.527516","url":null,"abstract":"<p><p>In this paper, we propose a covert communication scheme based on a spread spectrum for ultra-violet communication. We first characterize the system model of the communication system, where Warden is adopted to monitor the legitimated user transmission based on the binary hypothesis test and Kolmogorov-Smirnov test. To avoid periodic transmission of the pilot sequence which potentially degrades covertness, we propose a blind synchronization approach, such that the pilot sequence does not need to be transmitted. It is observed from system-level simulation that the spread spectrum-based approach can achieve both low detection bit error rate and covertness under weak light intensity. Moreover, we experimentally evaluate the detection performance and covertness of the proposed approach.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"32 15","pages":"25981-25994"},"PeriodicalIF":3.2,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142625601","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-range dipole-dipole exchange-induced atomic grating.","authors":"Xuan-Qian Bao, Xue-Dong Tian, Dong-Xiao Li, Yi-Mou Liu","doi":"10.1364/OE.526111","DOIUrl":"https://doi.org/10.1364/OE.526111","url":null,"abstract":"<p><p>We propose a theoretical scheme for dipole exchange-induced grating (DEIG) based on a hybrid coherent atomic system. The system consists of an ultra-cold rubidium (⁸⁷Rb) atomic ensemble and movable Rydberg spin atoms. The optical response of the grating appears as a superposition of three- and four-level configurations, which is similar to the cooperative optical nonlinearity caused by the dipole blockade effect. The far-field diffraction properties of the cooperative optical nonlinear grating are tuned by the probe field (intensity and photon statistics). However, our Rydberg atomic grating uniquely responds to the spatial positions of spin atoms, which offers a novel approach to dynamically control electromagnetically induced gratings (EIG).</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"32 15","pages":"25661-25675"},"PeriodicalIF":3.2,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142625559","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":"Optoelectronic nonlinear Softmax operator based on diffractive neural networks.","authors":"Ziyu Zhan, Hao Wang, Qiang Liu, Xing Fu","doi":"10.1364/OE.527843","DOIUrl":"https://doi.org/10.1364/OE.527843","url":null,"abstract":"<p><p>Softmax, a pervasive nonlinear operation, plays a pivotal role in numerous statistics and deep learning (DL) models such as ChatGPT. To compute it is expensive especially for at-scale models. Several software and hardware speed-up strategies are proposed but still suffer from low efficiency, poor scalability. Here we propose a photonic-computing solution including massive programmable neurons that is capable to execute such operation in an accurate, computation-efficient, robust and scalable manner. Experimental results show our diffraction-based computing system exhibits salient generalization ability in diverse artificial and real-world tasks (mean square error <10^-5). We further analyze its performances against several realistic restricted factors. Such flexible system not only contributes to optimizing Softmax operation mechanism but may provide an inspiration of manufacturing a plug-and-play module for general optoelectronic accelerators.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"32 15","pages":"26458-26469"},"PeriodicalIF":3.2,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142625584","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":"Tailoring resonant modes in dual cavities for transmissive structural colors with high brightness and high purity.","authors":"Incheol Jung, Hyeonwoo Kim, Seongcheol Ju, Donggyu Kim, Hojae Kwak, Haozhu Wang, L Jay Guo, Hui Joon Park, Jong G Ok, Kyu-Tae Lee","doi":"10.1364/OE.528618","DOIUrl":"https://doi.org/10.1364/OE.528618","url":null,"abstract":"<p><p>We present quad-layered structural color filters producing transmissive red (R), green (G), and blue (B) colors with high brightness and high purity, where thicknesses of layers for the RGB colors are optimized by using a L-BFGS-B algorithm. To evaluate the performance of the proposed structural color filters, computer-based inverse designs based on meta-heuristic and reinforcement learning algorithms are employed, where the optical properties obtained from the inverse designs are comparable to those shown in our proposed design. A peak separation phenomenon in dual cavities is applied to make a spectral response rectangular, and also a resonance order is optimally tailored to maximize the transmittance at a resonant wavelength with the suppression of undesired higher-order resonances at the same time for achieving pure colors. Transmission efficiency over 75% and the full width at half-maximum (FWHM) less than 90 nm are achieved. Besides, selecting a cavity medium with a high refractive index allows the optical properties of the structural color filters to remain almost constant in wavelength over a broad range of incident angles up to 60°. Moreover, only a few deposition steps are necessary, thus leading to a much simple fabrication as compared to previous works that involve a series of complicated lithographic processes. The approach described in this study may provide new ways for achieving diverse applications, such as displays, imaging devices, decorations, and colored solar cells.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"32 15","pages":"26136-26146"},"PeriodicalIF":3.2,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142625616","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}