RESUMO
Advancements in optical coherence control1-5 have unlocked many cutting-edge applications, including long-haul communication, light detection and ranging (LiDAR) and optical coherence tomography6-8. Prevailing wisdom suggests that using more coherent light sources leads to enhanced system performance and device functionalities9-11. Our study introduces a photonic convolutional processing system that takes advantage of partially coherent light to boost computing parallelism without substantially sacrificing accuracy, potentially enabling larger-size photonic tensor cores. The reduction of the degree of coherence optimizes bandwidth use in the photonic convolutional processing system. This breakthrough challenges the traditional belief that coherence is essential or even advantageous in integrated photonic accelerators, thereby enabling the use of light sources with less rigorous feedback control and thermal-management requirements for high-throughput photonic computing. Here we demonstrate such a system in two photonic platforms for computing applications: a photonic tensor core using phase-change-material photonic memories that delivers parallel convolution operations to classify the gaits of ten patients with Parkinson's disease with 92.2% accuracy (92.7% theoretically) and a silicon photonic tensor core with embedded electro-absorption modulators (EAMs) to facilitate 0.108 tera operations per second (TOPS) convolutional processing for classifying the Modified National Institute of Standards and Technology (MNIST) handwritten digits dataset with 92.4% accuracy (95.0% theoretically).
Assuntos
Redes Neurais de Computação , Óptica e Fotônica , Fótons , Tomografia de Coerência Óptica , Humanos , Óptica e Fotônica/instrumentação , Óptica e Fotônica/métodos , Doença de Parkinson/diagnóstico , Doença de Parkinson/fisiopatologia , Silício/química , Tomografia de Coerência Óptica/instrumentação , Tomografia de Coerência Óptica/métodos , Marcha/fisiologia , Conjuntos de Dados como Assunto , Sensibilidade e EspecificidadeRESUMO
Differentiation between leukocyte subtypes like monocytes and lymphocytes is essential for cell therapy and research applications. To guarantee the cost-effective delivery of functional cells in cell therapies, billions of cells must be processed in a limited time. Yet, the sorting rates of commercial cell sorters are not high enough to reach the required yield. Process parallelization by using multiple instruments increases variability and production cost. A compact solution with higher throughput can be provided by multichannel flow cytometers combining fluidics and optics on-chip. In this work, we present a micro-flow cytometer with monolithically integrated photonics and fluidics and demonstrate that both the illumination of cells, as well as the collection of scattered light, can be realized using photonic integrated circuits. Our device is the first with sufficient resolution for the discrimination of lymphocytes and monocytes. Innovations in microfabrication have enabled complete integration of miniaturized photonic components and fluidics in a CMOS-compatible wafer stack. In combination with external optics, the device is ready for the collection of fluorescence using the on-chip excitation.
Assuntos
Citometria de Fluxo , Dispositivos Lab-On-A-Chip , Leucócitos , Humanos , Citometria de Fluxo/métodos , Citometria de Fluxo/instrumentação , Leucócitos/citologia , Óptica e Fotônica/instrumentação , Óptica e Fotônica/métodos , Monócitos/citologia , Linfócitos/citologia , Desenho de EquipamentoRESUMO
Integrated microwave photonics (MWP) is an intriguing technology for the generation, transmission and manipulation of microwave signals in chip-scale optical systems1,2. In particular, ultrafast processing of analogue signals in the optical domain with high fidelity and low latency could enable a variety of applications such as MWP filters3-5, microwave signal processing6-9 and image recognition10,11. An ideal integrated MWP processing platform should have both an efficient and high-speed electro-optic modulation block to faithfully perform microwave-optic conversion at low power and also a low-loss functional photonic network to implement various signal-processing tasks. Moreover, large-scale, low-cost manufacturability is required to monolithically integrate the two building blocks on the same chip. Here we demonstrate such an integrated MWP processing engine based on a 4 inch wafer-scale thin-film lithium niobate platform. It can perform multipurpose tasks with processing bandwidths of up to 67 GHz at complementary metal-oxide-semiconductor (CMOS)-compatible voltages. We achieve ultrafast analogue computation, namely temporal integration and differentiation, at sampling rates of up to 256 giga samples per second, and deploy these functions to showcase three proof-of-concept applications: solving ordinary differential equations, generating ultra-wideband signals and detecting edges in images. We further leverage the image edge detector to realize a photonic-assisted image segmentation model that can effectively outline the boundaries of melanoma lesion in medical diagnostic images. Our ultrafast lithium niobate MWP engine could provide compact, low-latency and cost-effective solutions for future wireless communications, high-resolution radar and photonic artificial intelligence.
Assuntos
Micro-Ondas , Nióbio , Óptica e Fotônica , Óxidos , Fótons , Inteligência Artificial , Diagnóstico por Imagem/instrumentação , Diagnóstico por Imagem/métodos , Melanoma/diagnóstico por imagem , Melanoma/patologia , Óptica e Fotônica/instrumentação , Óptica e Fotônica/métodos , Radar , Tecnologia sem Fio , HumanosRESUMO
A photonic crystal fiber (PCF)-based fluorescence sensor is developed for rapid and sensitive detection of lactic acid (LA) enantiomers in serum samples. The sensor is fabricated by chemical binding dual enzymes on the inner surface of the PCF with numerous pore structures and a large specific surface area, which is suitable to be utilized as an enzymatic reaction carrier. To achieve simultaneous detection of L-LA and D-LA, the PCF with an aldehyde-activated surface is cut into two separate pieces, one of which is coated with L-LDH/GPT enzymes and the other with D-LDH/GPT enzymes. By being connected and carefully aligned to each other by a suitable sleeve tube connector, the responses of both L-LA and D-LA sensors are determined by laser-induced flourescence (LIF) detection. With the aid of enzyme-linked catalytic reactions, the proposed PCF sensor can greatly improve the sensitivity and analysis speed for the detection of LA enantiomers. The PCF sensor exhibits a low limit of detection of 9.5 µM and 0.8 µM, and a wide linear range of 25-2000 µM and 2-400 µM for L-LA and D-LA, respectively. The sensor has been successfully applied to accurate determination of LA enantiomers in human serum with satisfactory reproducibility and stability. It is indicated that the present PCF sensors would be used as an attractive analytical platform for quantitative detection of trace-amount LA enantiomers in real biological samples, and thus would play a role in disease diagnosis and clinical monitoring in point-of-care testing.
Assuntos
Ácido Láctico/análise , Óptica e Fotônica/instrumentação , Óptica e Fotônica/métodos , Enzimas Imobilizadas/química , Desenho de Equipamento , Fluorescência , Humanos , L-Lactato Desidrogenase/química , Ácido Láctico/sangue , Ácido Láctico/química , Lasers , Limite de Detecção , Microscopia Eletrônica de Varredura , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Espectroscopia de Infravermelho com Transformada de Fourier , EstereoisomerismoRESUMO
Several applications in health diagnostics, food, safety, and environmental monitoring require rapid, simple, selective, and quantitatively accurate viral load monitoring. Here, we introduce the first label-free biosensing method that rapidly detects and quantifies intact virus in human saliva with single-virion resolution. Using pseudotype SARS-CoV-2 as a representative target, we immobilize aptamers with the ability to differentiate active from inactive virions on a photonic crystal, where the virions are captured through affinity with the spike protein displayed on the outer surface. Once captured, the intrinsic scattering of the virions is amplified and detected through interferometric imaging. Our approach analyzes the motion trajectory of each captured virion, enabling highly selective recognition against nontarget virions, while providing a limit of detection of 1 × 103 copies/mL at room temperature. The approach offers an alternative to enzymatic amplification assays for point-of-collection diagnostics.
Assuntos
Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais/métodos , DNA/química , Ácidos Nucleicos Imobilizados/química , SARS-CoV-2/isolamento & purificação , Técnicas Biossensoriais/instrumentação , Humanos , Limite de Detecção , Microscopia/métodos , Óptica e Fotônica/instrumentação , Óptica e Fotônica/métodos , SARS-CoV-2/química , Saliva/virologia , Glicoproteína da Espícula de Coronavírus/químicaRESUMO
Biological lasers which utilize Fabry-Pérot (FP) cavities have attracted tremendous interest due to their potential in amplifying subtle biological changes. Transverse laser modes generated from cells serve as distinct fingerprints of individual cells; however, most lasing signals lack the ability to provide key information about the cell due to high complexity of transverse modes. The missing key, therefore, hinders it from practical applications in biomedicine. This study reveals the key mechanism governing the frequency distributions of transverse modes in cellular lasers. Spatial information of cells including curvature can be interpreted through spectral information of transverse modes by means of hyperspectral imaging. Theoretical studies are conducted to explore the correlation between the cross-sectional morphology of a cell and lasing frequencies of transverse modes. Experimentally, the spectral characteristics of transverse modes are investigated in live and fixed cells with different morphological features. By extracting laser modes in frequency domain, the proposed concept is applied for studying cell adhesion process and cell classification from rat cortices. This study expands a new analytical dimension of cell lasers, opening an avenue for subcellular analysis in biophotonic applications.
Assuntos
Adesão Celular/fisiologia , Lasers , Óptica e Fotônica/instrumentação , Óptica e Fotônica/métodos , Animais , Desenho de Equipamento , Luz , Modelos Animais , Modelos Teóricos , RatosRESUMO
Micro-lens array is a great example of bio-mimetic technology which was inspired by compound eyes found in insects and is used in lasers, optical communication, and 3D imaging. In this study, a micro-lens array was fabricated from cyclic olefin copolymer using a cost-effective method: compression molding and thermal reflow. Also, a light screen was installed between lenses to reduce the optical interference for clearer individual images. Cyclic olefin copolymer-based micro-lens array showed good optical results under a standard optical microscope. By placing the fabricated micro-lens array directly on an image sensor, it was observed that the light screen shows significant improvement in image quality. Also, the point spread function was analyzed to confirm the optical performance and the effectiveness of the micro-lens array with the light screen installed.
Assuntos
Alcenos/química , Biomimética/instrumentação , Lentes , Luz , Óptica e Fotônica/instrumentação , Análise Custo-Benefício , Desenho de Equipamento , Óptica e Fotônica/economiaRESUMO
Optical microrobotics is an emerging field that has the potential to improve upon current optical tweezer studies through avenues such as limiting the exposure of biological molecules of interest to laser radiation and overcoming the current limitations of low forces and unwanted interactions between nearby optical traps. However, optical microrobotics has been historically limited to rigid, single-body end-effectors rather than even simple machines, limiting the tasks that can be performed. Additionally, while multi-body machines such as microlevers exist in the literature, they have not yet been successfully demonstrated as tools for biological studies, such as molecule stretching. In this work we have taken a step towards moving the field forward by developing two types of microlever, produced using two-photon absorption polymerisation, to perform the first lever-assisted stretches of double-stranded DNA. The aim of the work is to provide a proof of concept for using optical micromachines for single molecule studies. Both styles of microlevers were successfully used to stretch single duplexes of DNA, and the results were analysed with the worm-like chain model to show that they were in good agreement.
Assuntos
DNA , Conformação de Ácido Nucleico , Pinças Ópticas , Estudo de Prova de Conceito , Robótica/métodos , Óptica e Fotônica/instrumentação , Óptica e Fotônica/métodos , Robótica/instrumentaçãoRESUMO
Light plays paramount functions for living beings in nature. In addition to color, the polarization of light is used by many animals for navigation and communication. In this study, we describe the light polarizing role of special nanostructures coating cuticular surfaces of diverse arthropods. These structures are built as parallel nanoscale ridges covering the eyes of the sunlight-navigating spider Drassodes lapidosus and of the water pond-swarming black fly Simulium vittatum, as well as the light-emitting abdominal lantern of the firefly Aquatica lateralis. Exact topography and dimensions of the parallel nanoridges provide different light polarizing efficiencies and wavelength sensitivity. Optical modeling confirms that the nanoscale ridges are responsible for the spectral polarization dependency. Co-opting from our recent work on the self-assembly of Drosophila corneal nanostructures, we engineer arthropod-like parallel nanoridges on artificial surfaces, which recapitulate the light polarization effects. Our work highlights the fundamental importance of nanocoatings in arthropods for the light polarization management and provides a new biomimetic approach to produce ordered nanostructures under mild conditions.
Assuntos
Materiais Biomiméticos/química , Biomimética/instrumentação , Modelos Biológicos , Nanoestruturas/química , Óptica e Fotônica/instrumentação , Animais , Bioengenharia , Olho Composto de Artrópodes/química , Córnea/química , Córnea/fisiologia , Drosophila , Vaga-Lumes , Luz , AranhasRESUMO
Light guiding and manipulation in photonics have become ubiquitous in events ranging from everyday communications to complex robotics and nanomedicine. The speed and sensitivity of light-matter interactions offer unprecedented advantages in biomedical optics, data transmission, photomedicine, and detection of multi-scale phenomena. Recently, hydrogels have emerged as a promising candidate for interfacing photonics and bioengineering by combining their light-guiding properties with live tissue compatibility in optical, chemical, physiological, and mechanical dimensions. Herein, the latest progress over hydrogel photonics and its applications in guidance and manipulation of light is reviewed. Physics of guiding light through hydrogels and living tissues, and existing technical challenges in translating these tools into biomedical settings are discussed. A comprehensive and thorough overview of materials, fabrication protocols, and design architectures used in hydrogel photonics is provided. Finally, recent examples of applying structures such as hydrogel optical fibers, living photonic constructs, and their use as light-driven hydrogel robots, photomedicine tools, and organ-on-a-chip models are described. By providing a critical and selective evaluation of the field's status, this work sets a foundation for the next generation of hydrogel photonic research.
Assuntos
Hidrogéis/química , Hidrogéis/metabolismo , Óptica e Fotônica/instrumentação , Animais , Materiais Biocompatíveis/química , Técnicas de Cultura de Células , Sistemas de Liberação de Medicamentos , Tecido Elástico/química , Equipamentos e Provisões , Humanos , Impressão Tridimensional , Propriedades de Superfície , Engenharia TecidualRESUMO
We propose an approach to realize an optically transparent microwave absorber based on water-based moth-eye metamaterial structures. The absorber is made of a periodic array of properly shaped glass caps infiltrated with distilled water. Analytical calculations and numerical simulations show that the water-based metamaterial absorbs electromagnetic waves over a wide spectral band ranging from 4GHz to well above 120GHz, showing absorption levels close to 100% for incident radiation that ranges from normal to grazing angles, for both TE and TM polarizations. Yet, the structure is optically transparent, offering exciting opportunities in a variety of civil and military applications, such as for camouflage and shielding systems and in energy harvesting structures.
Assuntos
Olho , Micro-Ondas , Mariposas , Óptica e Fotônica/instrumentação , Radar , Animais , Óptica e Fotônica/métodosRESUMO
One of the disadvantages in microscope-integrated optical coherence tomography (MI-OCT) systems is that medical images acquired via different modalities are usually displayed independently. Hence, surgeons have to match two-dimensional and three-dimensional images of the same operative region subjectively. In this paper, we propose a simple registration method to overcome this problem by using guided laser points. This method combines augmented reality with an existing MI-OCT system. The basis of our idea is to introduce a guiding laser into the system, which allows us to identify fiducials in microscopic images. At first, the applied voltages of the scanning galvanometer mirror are used to calculate the fiducials' coordinates in an OCT model. After gathering data at the corresponding points' coordinates, the homography matrix and camera parameters are used to superimpose a reconstructed model on microscopic images. After performing experiments with artificial and animal eyes, we successfully obtain two-dimensional microscopic images of scanning regions with depth information. Moreover, the registration error is 0.04â mm, which is within the limits of medical and surgical errors. Our proposed method could have many potential applications in ophthalmic procedures.
Assuntos
Realidade Aumentada , Imageamento Tridimensional , Microscopia , Óptica e Fotônica/métodos , Tomografia de Coerência Óptica/métodos , Marcadores Fiduciais , Humanos , Erros Médicos , Óptica e Fotônica/instrumentação , Tomografia de Coerência Óptica/instrumentaçãoRESUMO
It has been demonstrated that optically controlled microcurrents can be used to capture and move around a variety of microscopic objects ranging from cells and nanowires to whole live worms. Here, we present our findings on several new regimes of optofluidic manipulation that can be engineered using careful design of microcurrents. We theoretically optimize these regimes using COMSOL Multiphysics and present three sets of simulations and corresponding optofluidic experiments. In the first regime, we use local fluid heating to create a microcurrent with a symmetric toroid shape capturing particles in the center. In the second regime, the microcurrent shifts and tilts because external fluid flow is introduced into the microfluidic channel. In the third regime, the whole microfluidic channel is tilted, and the resulting microcurrent projects particles in a fan-like fashion. All three configurations provide interesting opportunities to manipulate small particles in fluid droplets and microfluidic channels.
Assuntos
Técnicas Analíticas Microfluídicas/instrumentação , Microfluídica/instrumentação , Óptica e Fotônica/instrumentação , Simulação por Computador , Lasers , Metais/química , Modelos Químicos , Fibras Ópticas , Dióxido de Silício/químicaRESUMO
Interferometric scattering microscopy is increasingly employed in biomedical research owing to its extraordinary capability of detecting nano-objects individually through their intrinsic elastic scattering. To significantly improve the signal-to-noise ratio without increasing illumination intensity, we developed photonic resonator interferometric scattering microscopy (PRISM) in which a dielectric photonic crystal (PC) resonator is utilized as the sample substrate. The scattered light is amplified by the PC through resonant near-field enhancement, which then interferes with the <1% transmitted light to create a large intensity contrast. Importantly, the scattered photons assume the wavevectors delineated by PC's photonic band structure, resulting in the ability to utilize a non-immersion objective without significant loss at illumination density as low as 25 W cm-2. An analytical model of the scattering process is discussed, followed by demonstration of virus and protein detection. The results showcase the promise of nanophotonic surfaces in the development of resonance-enhanced interferometric microscopies.
Assuntos
Microscopia de Interferência/instrumentação , Microscopia de Interferência/métodos , Óptica e Fotônica/instrumentação , Óptica e Fotônica/métodos , Cristalização , Desenho de Equipamento , Ouro , Processamento de Imagem Assistida por Computador , Nanopartículas Metálicas , Nanoestruturas , Fótons , Proteínas/isolamento & purificação , Vírion/isolamento & purificação , Vírus/isolamento & purificaçãoRESUMO
The purpose of this study was to analyse the reliability and validity of an opto-electronic sensor system (Velowin) for assessment of the bar-velocity in the deep squat exercise. Mean velocity, mean propulsive velocity and peak velocity generated in the deep squat exercise performed in the Smith machine bar were analysed compared to a linear velocity transducer considered as the gold standard. The study was conducted with a sample of 26 men with experience in resistance training. Six measurements were analysed for squat exercise in concentric phase using a progressive loading increase. Three consecutive repetitions were performed per load with a 3-4 min recovery between loads. Analysis of variance confirmed that there were no significant differences (p > 0.05) for the velocity variables between Velowin and T-Force for each of the loads. The reliability analysis showed high values of the intraclass correlation coefficient (ICC = 0.94-0.99), an 'almost perfect' Lin's concordance coefficient (CCC = 0.99) and a low coefficient of variation (CV <3.4%) for each of the loads and velocities. These results confirm the reliability and validity of the Velowin device for measuring the execution velocity in deep squat exercise.
Assuntos
Exercício Físico/fisiologia , Movimento/fisiologia , Óptica e Fotônica/instrumentação , Treinamento Resistido , Adulto , Fenômenos Biomecânicos , Equipamentos e Provisões Elétricas , Humanos , Masculino , Reprodutibilidade dos TestesRESUMO
Cyanobacterial blooms produce hazardous toxins, deplete oxygen, and secrete compounds that confer undesirable organoleptic properties to water. To prevent bloom appearance, the World Health Organization has established an alert level between 500 and 2000 cells·mL-1, beyond the capabilities of most optical sensors detecting the cyanobacteria fluorescent pigments. Flow cytometry, cell culturing, and microscopy may reach these detection limits, but they involve both bulky and expensive laboratory equipment or long and tedious protocols. Thus, no current technology allows fast, sensitive, and in situ detection of cyanobacteria. Here, we present a simple, user-friendly, low-cost, and portable photonic system for in situ detection of low cyanobacterial concentrations in water samples. The system integrates high-performance preconcentration elements and optical components for fluorescence measurement of specific cyanobacterial pigments, that is, phycocyanin. Phycocyanin has demonstrated to be more selective to cyanobacteria than other pigments, such as chlorophyll-a, and to present an excellent linear correlation with bacterial concentration from 102 to 104 cell·mL-1 (R2 = 0.99). Additionally, the high performance of the preconcentration system leads to detection limits below 435 cells·mL-1 after 10 min in aquaponic water samples. Due to its simplicity, compactness, and sensitivity, we envision the current technology as a powerful tool for early warning and detection of low pathogen concentrations in water samples.
Assuntos
Clorofila A/química , Monitoramento Ambiental/métodos , Eutrofização , Óptica e Fotônica/instrumentação , Óptica e Fotônica/métodos , Synechocystis/fisiologia , Aquicultura , Monitoramento Ambiental/instrumentação , Pigmentos Biológicos/química , Microbiologia da ÁguaRESUMO
Correlative light and electron microscopy (CLEM) unifies the versatility of light microscopy (LM) with the high resolution of electron microscopy (EM), allowing one to zoom into the complex organization of cells. Here, we introduce photonic chip assisted CLEM, enabling multi-modal total internal reflection fluorescence (TIRF) microscopy over large field of view and high precision localization of the target area of interest within EM. The photonic chips are used as a substrate to hold, to illuminate and to provide landmarking of the sample through specially designed grid-like numbering systems. Using this approach, we demonstrate its applicability for tracking the area of interest, imaging the three-dimensional (3D) structural organization of nano-sized morphological features on liver sinusoidal endothelial cells such as fenestrations (trans-cytoplasmic nanopores), and correlating specific endo-lysosomal compartments with its cargo protein upon endocytosis.
Assuntos
Células Endoteliais , Microscopia/métodos , Óptica e Fotônica/instrumentação , Animais , Fígado/citologia , Masculino , Ratos , Ratos Sprague-DawleyRESUMO
Polymer dispersed liquid crystals (PDLCs) have kindled a spark of interest because of their unique characteristic of electrically controlled switching. However, some issues including high operating voltage, low contrast ratio and poor mechanical properties are hindering their practical applications. To overcome these drawbacks, some measures were taken such as molecular structure optimization of the monomers and liquid crystals, modification of PDLC and doping of nanoparticles and dyes. This review aims at detailing the recent advances in the process, preparations and applications of PDLCs over the past six years.