Optica最新文献

{"title":"Celebrating the Tenth Anniversary of Optica: editorial","authors":"Prem Kumar","doi":"10.1364/optica.553433","DOIUrl":"https://doi.org/10.1364/optica.553433","url":null,"abstract":"<jats:italic toggle=\"yes\">Optica</jats:italic> Editor-in-Chief Prem Kumar reviews the first ten years of the Journal.","PeriodicalId":19515,"journal":{"name":"Optica","volume":"20 1","pages":""},"PeriodicalIF":10.4,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142857907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Hybrid dark-field and attenuation contrast retrieval for laboratory-based X-ray tomography.","authors":"Adam Doherty, Ian Buchanan, Oriol Roche I Morgó, Alberto Astolfo, Savvas Savvidis, Mattia F M Gerli, Antonio Citro, Alessandro Olivo, Marco Endrizzi","doi":"10.1364/OPTICA.525760","DOIUrl":"10.1364/OPTICA.525760","url":null,"abstract":"<p><p>X-ray dark-field imaging highlights sample structures through contrast generated by sub-resolution features within the inspected volume. Quantifying dark-field signals generally involves multiple exposures for phase retrieval, separating contributions from scattering, refraction, and attenuation. Here, we introduce an approach for non-interferometric X-ray dark-field imaging that presents a single-parameter representation of the sample. This fuses attenuation and dark-field signals, enabling the reconstruction of a unified three-dimensional volume. Notably, our method can obtain dark-field contrast from a single exposure and employs conventional back projection algorithms for reconstruction. Our approach is based on the assumption of a macroscopically homogeneous material, which we validate through experiments on phantoms and on biological tissue samples. The methodology is implemented on a laboratory-based, rotating anode X-ray tube system without the need for coherent radiation or a high-resolution detector. Utilizing this system with streamlined data acquisition enables expedited scanning while maximizing dose efficiency. These attributes are crucial in time- and dose-sensitive medical imaging applications and unlock the ability of dark-field contrast with high-throughput lab-based tomography. We believe that the proposed approach can be extended across X-ray dark-field imaging implementations beyond tomography, spanning fast radiography, directional dark-field imaging, and compatibility with pulsed X-ray sources.</p>","PeriodicalId":19515,"journal":{"name":"Optica","volume":"11 12","pages":"1603-1613"},"PeriodicalIF":8.4,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11674740/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142903341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrated chirped photonic-crystal cavities in gallium phosphide for broadband soliton generation","authors":"Alberto Nardi, Alisa Davydova, Nikolai Kuznetsov, Miles H. Anderson, Charles Möhl, Johann Riemensberger, Tobias J. Kippenberg, Paul Seidler","doi":"10.1364/optica.530247","DOIUrl":"https://doi.org/10.1364/optica.530247","url":null,"abstract":"Chirped mirrors have underpinned advances in ultra-fast lasers based on bulk optics but have yet to be fully exploited in integrated photonics, where they could provide a means to engineer otherwise unattainable dispersion profiles for a range of nonlinear optical applications, including soliton frequency comb generation. The vast majority of integrated resonators for frequency combs make use of microring geometries, in which only waveguide width and height are varied to engineer dispersion. Here, we present an integrated photonic-crystal Fabry–Pérot resonator made of gallium phosphide (GaP), a material exhibiting a Kerr nonlinearity 200 times larger than that of silicon nitride and a high refractive index that permits the creation of strongly chirped photonic-crystal mirrors. Leveraging the additional degrees of freedom provided by integrated chirped mirrors, we disentangle optical losses from dispersion. We obtain an overall dispersion that is more anomalous than that achievable in both silicon nitride and gallium phosphide ring resonators with the same free-spectral range (FSR), while simultaneously obtaining higher quality factors than those of GaP ring resonators. With subharmonic pulsed pumping at an average power of 23.6 mW, we are able to access stable dissipative Kerr frequency combs in a device with a FSR of 55.9 GHz. We demonstrate soliton formation with a 3-dB bandwidth of 3.0 THz, corresponding to a pulse duration of 60 fs. This approach to cavity design based on photonic-crystal reflectors offers nearly arbitrary dispersion engineering over the optical transparency window of the nonlinear material.","PeriodicalId":19515,"journal":{"name":"Optica","volume":"22 1","pages":""},"PeriodicalIF":10.4,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142443863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Photonic and electrochemical biosensors for near-patient tests-a critical comparison.","authors":"Thomas F Krauss, Lisa Miller, Christoph Wälti, Steven Johnson","doi":"10.1364/OPTICA.530068","DOIUrl":"10.1364/OPTICA.530068","url":null,"abstract":"<p><p>Research into diagnostic biosensors is a vibrant field that combines scientific challenge with translational opportunities; innovation in healthcare is of great societal interest and is an essential element of future healthcare provision. Photonic and electrochemical biosensors are the dominant modalities, both scientifically and commercially, yet the two scientific communities largely remain separated and siloed. It seems astute to better understand what the two fields can learn from one another so as to progress the key scientific, translational, and commercial challenges. Here, we provide an analysis of the fundamental operational characteristics of photonic and electrochemical biosensors using a classification based on energy transfer; in photonics, this separates refractive index sensors from fluorescence and vibrational spectroscopy, while in electrochemistry, it distinguishes Faradaic from non-Faradaic processes. This classification allows us to understand some of the key performance characteristics, such as the susceptibility to fouling and dependence on the clinical matrix that is being analyzed. We discuss the use of labels and the ultimate performance limits, and some of the unique advantages of photonics, such as multicolor operation and fingerprinting, and critically evaluate the requirements for translation of these technologies for clinical use. We trust that this critical review will inform future research in biosensors and support both scientific and commercial developments.</p>","PeriodicalId":19515,"journal":{"name":"Optica","volume":"11 10","pages":"1408-1418"},"PeriodicalIF":8.4,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11601118/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142751157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-speed two-photon microscopy with adaptive line-excitation.","authors":"Yunyang Li, Shu Guo, Ben Mattison, Junjie Hu, Kwun Nok Mimi Man, Weijian Yang","doi":"10.1364/OPTICA.529930","DOIUrl":"10.1364/OPTICA.529930","url":null,"abstract":"<p><p>We present a two-photon fluorescence microscope designed for high-speed imaging of neural activity at cellular resolution. Our microscope uses an adaptive sampling scheme with line illumination. Instead of building images pixel by pixel via scanning a diffraction-limited spot across the sample, our scheme only illuminates the regions of interest (i.e., neuronal cell bodies) and samples a large area of them in a single measurement. Such a scheme significantly increases the imaging speed and reduces the overall laser power on the brain tissue. Using this approach, we performed high-speed imaging of the neuronal activity in mouse cortex <i>in vivo</i>. Our method provides a sampling strategy in laser-scanning two-photon microscopy and will be powerful for high-throughput imaging of neural activity.</p>","PeriodicalId":19515,"journal":{"name":"Optica","volume":"11 8","pages":"1138-1145"},"PeriodicalIF":8.4,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11601119/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142751231","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photonic quantum walk with ultrafast time-bin encoding","authors":"Kate L. Fenwick, Frédéric Bouchard, Guillaume S. Thekkadath, Duncan England, Philip J. Bustard, Khabat Heshami, Benjamin Sussman","doi":"10.1364/optica.510312","DOIUrl":"https://doi.org/10.1364/optica.510312","url":null,"abstract":"The quantum walk (QW) has proven to be a valuable testbed for fundamental inquiries in quantum technology applications such as quantum simulation and quantum search algorithms. Many benefits have been found by exploring implementations of QWs in various physical systems, including photonic platforms. Here, we propose a platform to perform quantum walks based on ultrafast time-bin encoding (UTBE) and all-optical Kerr gating. This platform supports the scalability of quantum walks to a large number of steps and walkers while retaining a significant degree of programmability. More importantly, ultrafast time bins are encoded at the picosecond time scale, far away from mechanical fluctuations. This enables the scalability of our platform to many modes while preserving excellent interferometric phase stability over extremely long periods of time without requiring active phase stabilization. Our 18-step QW is shown to preserve interferometric phase stability over a period of 50 h, with an overall walk fidelity maintained above 95%.","PeriodicalId":19515,"journal":{"name":"Optica","volume":"74 1","pages":""},"PeriodicalIF":10.4,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Control-free and efficient integrated photonic neural networks via hardware-aware training and pruning","authors":"Tengji Xu, Weipeng Zhang, Jiawei Zhang, Zeyu Luo, Qiarong Xiao, Benshan Wang, Mingcheng Luo, Xingyuan Xu, Bhavin J. Shastri, Paul R. Prucnal, Chaoran Huang","doi":"10.1364/optica.523225","DOIUrl":"https://doi.org/10.1364/optica.523225","url":null,"abstract":"Integrated photonic neural networks (PNNs) are at the forefront of AI computing, leveraging light’s unique properties, such as large bandwidth, low latency, and potentially low power consumption. Nevertheless, the integrated optical components are inherently sensitive to external disturbances, thermal interference, and various device imperfections, which detrimentally affect computing accuracy and reliability. Conventional solutions use complicated control methods to stabilize optical devices and chip, which result in high hardware complexity and are impractical for large-scale PNNs. To address this, we propose a training approach to enable control-free, accurate, and energy-efficient photonic computing without adding hardware complexity. The core idea is to train the parameters of a physical neural network towards its noise-robust and energy-efficient region. Our method is validated on different integrated PNN architectures and is applicable to solve various device imperfections in thermally tuned PNNs and PNNs based on phase change materials. A notable 4-bit improvement is achieved in micro-ring resonator-based PNNs without needing complex device control or power-hungry temperature stabilization circuits. Additionally, our approach reduces the energy consumption by tenfold. This advancement represents a significant step towards the practical, energy-efficient, and noise-resilient implementation of large-scale integrated PNNs.","PeriodicalId":19515,"journal":{"name":"Optica","volume":"31 1","pages":""},"PeriodicalIF":10.4,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Piezoelectrically tunable, narrow linewidth photonic integrated extended-DBR lasers","authors":"Anat Siddharth, Alaina Attanasio, Simone Bianconi, Grigory Lihachev, Junyin Zhang, Zheru Qiu, Andrea Bancora, Scott Kenning, Rui Ning Wang, Andrey S. Voloshin, Sunil A. Bhave, Johann Riemensberger, Tobias J. Kippenberg","doi":"10.1364/optica.524703","DOIUrl":"https://doi.org/10.1364/optica.524703","url":null,"abstract":"Recent advancements in ultra-low-loss silicon nitride (Si<jats:sub>3</jats:sub>N<jats:sub>4</jats:sub>)-based photonic integrated circuits have surpassed fiber lasers in coherence and frequency agility. However, high manufacturing costs of DFB and precise control requirements, as required for self-injection locking, hinder widespread adoption. Reflective semiconductor optical amplifiers (RSOAs) provide a cost-effective alternative solution but have not yet achieved similar performance in coherence or frequency agility, as required for frequency modulated continuous wave (FMCW) LiDAR, laser locking in frequency metrology, or wavelength modulation spectroscopy for gas sensing. Here, we overcome this challenge and demonstrate an RSOA-based and frequency-agile fully hybrid integrated extended distributed Bragg reflector (E-DBR) laser with high-speed tuning, good linearity, high optical output power, and turn-key operability. It outperforms Vernier and self-injection locked lasers, which require up to five precise operating parameters and have limitations in continuous tuning and actuation bandwidth. We maintain a small footprint by utilizing an ultra-low-loss 200 nm thin Si<jats:sub>3</jats:sub>N<jats:sub>4</jats:sub> platform with monolithically integrated piezoelectric actuators. We co-integrate the DBR with a compact ultra-low-loss spiral resonator to further reduce the intrinsic optical linewidth of the laser to the Hertz-level—on par with the noise of a fiber laser—via self-injection locking. The photonic integrated E-DBR lasers operate at 1550 nm and feature up to 25 mW fiber-coupled output power in the free-running and up to 10.5 mW output power in the self-injection locked state. The intrinsic linewidth is 2.5 kHz in the free-running state and as low as 3.8 Hz in the self-injection locked state. In addition, we demonstrate the suitability for FMCW LiDAR by showing laser frequency tuning over 1.0 GHz at up to 100 kHz triangular chirp rate with a nonlinearity of less than 0.6% without linearization by modulating a Bragg grating using monolithically integrated aluminum nitride (AlN) piezoactuators.","PeriodicalId":19515,"journal":{"name":"Optica","volume":"46 1","pages":""},"PeriodicalIF":10.4,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Hyperentanglement quantum communication over a 50 km noisy fiber channel","authors":"Zhen-Qiu Zhong, Xiao-Hai Zhan, Jia-Lin Chen, Shuang Wang, Zhen-Qiang Yin, Jia-Qi Geng, De-Yong He, Wei Chen, Guang-Can Guo, Zheng-Fu Han","doi":"10.1364/optica.523955","DOIUrl":"https://doi.org/10.1364/optica.523955","url":null,"abstract":"High-dimensional entanglement not only offers a high security level for quantum communication but also promises improved information capacity and noise resistance of the system. However, due to various constraints on different high-dimensional degrees of freedom, whether these advantages can bring improvement to the actual implementation is still not well proven. Here we present a scheme to fully utilize these advantages over long-distance noisy fiber channels. We exploit polarization and time-bin hyperentanglement to achieve high-dimensional coding, and observe significant enhancements in secure key rates and noise tolerance that surpass the capabilities of qubit systems. Moreover, the demonstration achieves a distribution up to 50 km, which is the longest distance for high-dimensional entanglement-based quantum key distribution up to date, to our knowledge. Our demonstration validates the potential of high-dimensional entanglement for quantum communications over long-distance noisy channels, paving the way for a resilient and resource-efficient quantum network.","PeriodicalId":19515,"journal":{"name":"Optica","volume":"60 1","pages":""},"PeriodicalIF":10.4,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Electrically engineering synthetic magnetic fields for polarized photons","authors":"Guohua Liu, Zepei Zeng, Haolin Lin, Yanwen Hu, Zhen Li, Zhenqiang Chen, Shenhe Fu","doi":"10.1364/optica.527811","DOIUrl":"https://doi.org/10.1364/optica.527811","url":null,"abstract":"Polarized photons are, in essence, neutral particles and therefore do not couple directly to external fields, thus hampering the effective interaction of photons with external fields. Here, we theoretically identify an equivalent spin-1/2 model for polarized photons and synthesize a magnetization vector for coupling differently polarized photons in an engineered anisotropic medium. The synthetic magnetic field can be electrically engineered to manipulate the magnetic moments of the pseudo-spin-1/2 photons, leading to observation of the Lorentz force and analogous Stern–Gerlach effect. We experimentally demonstrate these fundamental effects by using different spins, including purely single-polarization spins and mutually two-polarization mixing spins. We also demonstrate the higher-order Stern–Gerlach effect by using spins having nontrivial topological structures. Our findings could enable polarization-based elements with potential applications in polarization selection and conversion, benefiting classical and quantum information processing.","PeriodicalId":19515,"journal":{"name":"Optica","volume":"13 1","pages":""},"PeriodicalIF":10.4,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}