- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Analysis of aberrations and performance evaluation of adaptive optics in two-photon light-sheet microscopy
摘要： Two-photon light-sheet microscopy (TP-LSM) system performance is greatly degraded by specimen-induced aberrations in illumination path, which limit the field of view, axial resolution and excitation efficiency of the system. Adaptive optics (AO) is an effective method for attenuating these effects. For the design and evaluation of an AO system, a comprehensive analysis of the effects of aberrations is needed. In this paper, a TP-LSM system is simulated, and new indexes based on integral intensity are introduced for the evaluation of an aberrated light-sheet. Then, the influences of each Zernike mode and random aberrations on the illumination path of the TP-LSM system are investigated with a numerical simulation method. Results show that high-order aberrations have little effect on the axial resolution and excitation efficiency of the system and only low-order components require correction. The random aberrations varied in strength with the depth of the specimens, so the number of corrected Zernike modes is variable. A general formula is generated for the estimation of the number of modes that should be detected and corrected under different aberrations and different numerical aperture of the objective. The results can provide important guidance in the design and evaluation of AO units for TP-LSM systems.
关键词： Two-photon Light-sheet Microscopy,Aberration correction,Adaptive optics
更新于2025-09-23 15:21:01
-
Quantum dots of two-dimensional Ruddlesdena??Popper organica??inorganic hybrid perovskite with high optical limiting properties
摘要： Hybrid perovskites have been investigated for various potential applications because of their tunable optical properties. In this paper, we report the synthesis of quantum dots (QDs) of two-dimensional (2D) Ruddlesden–Popper (RP) hybrid perovskite using a top-down approach. The QDs of the developed 2D RP perovskite exhibit high and sharp photoluminescence in the ultraviolet region. The sharp peak in the absorption spectrum and the intense photoluminescence in the ultraviolet region indicate strong quantum confinement in these particles, which is further confirmed by x-ray photoelectron spectroscopy. These QDs show superior nonlinear optical scattering and absorption properties with the optical z-scan technique and strong nonlinear absorption property with the photoacoustic z-scan technique. Evaluating the nonlinear optical properties using two complementary techniques provides a deeper understanding of the nonlinear mechanism involved in the optical limiting process. The two-photon absorption coefficient obtained by optical z-scan is 7.2 × 102 cm/GW, which is larger than that of most perovskite nanocrystals and nanosheets. Our studies, therefore, reveal a new class of material, 2D RP perovskite QDs, which show important nonlinear properties that are important for optical limiting applications.
关键词： Ruddlesden–Popper perovskite,optical limiting,nonlinear optical properties,Quantum dots,two-photon absorption
更新于2025-09-23 15:21:01
-
Feasibility Analysis of Nanostructured Planar Focusing Collectors for Concentrating Solar Power Applications
摘要： Concentrating solar power (CSP) technology is an attractive approach to harvesting solar energy. Unlike photovoltaic (PV) technology, thermal storage is used in lieu of batteries for electricity generation. However, the cost of current collection optics in a CSP plant hampers commercial competitiveness with PVs and natural gas. The use of a planar focusing collector (PFC) could help reduce cost of materials, installation, and maintenance. We present two candidate PFC designs, one based on metasurfaces and the other a Fresnel-like model. We feed each design through the entire system process—design, fabrication, scalability, and techno-economic feasibility—and discuss the challenges met at each stage. Two-photon and nanoimprint lithography are used to make PFC molds and replicas, respectively. We find that the annual optical efficiency for the Fresnel-based PFC is ~40%--higher than the current 30% target for natural gas, thereby suggesting potential economic advantages in the market of industrial process heat.
关键词： Metasurface,Two-Photon Lithography,Concentrating Solar Power (CSP),Planar Focusing Collector (PFC),Nanoimprint Lithography
更新于2025-09-23 15:21:01
-
<em>In Vivo</em> Two-photon Imaging of Cortical Neurons in Neonatal Mice
摘要： Two-photon imaging is a powerful tool for the in vivo analysis of neuronal circuits in the mammalian brain. However, a limited number of in vivo imaging methods exist for examining the brain tissue of live newborn mammals. Herein we summarize a protocol for imaging individual cortical neurons in living neonatal mice. This protocol includes the following two methodologies: (1) the Supernova system for sparse and bright labeling of cortical neurons in the developing brain, and (2) a surgical procedure for the fragile neonatal skull. This protocol allows the observation of temporal changes of individual cortical neurites during neonatal stages with a high signal-to-noise ratio. Labeled cell-specific gene silencing and knockout can also be achieved by combining the Supernova with RNA interference and CRISPR/Cas9 gene editing systems. This protocol can, thus, be used for analyzing the developmental dynamics of cortical neurons, molecular mechanisms that control the neuronal dynamics, and changes in neuronal dynamics in disease models.
关键词： Neuroscience,in vivo imaging,single-cell labeling,mouse,cerebral cortex,Newborn,two-photon
更新于2025-09-23 15:21:01
-
Ultrastrong-coupling regime of nondipolar light-matter interactions
摘要： We present a circuit-QED scheme which makes it possible to reach the ultrastrong-coupling regime of a nondipolar interaction between a single qubit and a quantum resonator. We show that the system Hamiltonian is well approximated by a two-photon quantum Rabi model and propose a simple scattering experiment to probe its fundamental properties. In particular, we identify a driving scheme that reveals the change in selection rules characterizing the breakdown of the rotating-wave approximation and the transition from strong to ultrastrong two-photon interactions. Finally, we show that a frequency crowding in a narrow spectral region is observable in the output fluorescence spectrum as the coupling strength approaches the collapse point, paving the way to the direct observation of the onset of the spectral collapse in a solid-state device.
关键词： nondipolar light-matter interactions,spectral collapse,two-photon quantum Rabi model,ultrastrong-coupling regime,circuit-QED
更新于2025-09-23 15:21:01
-
Versatile applications of three-dimensional objects fabricated by two-photon-initiated polymerization
摘要： In this topical review of two-photon stereolithography (TPS), we discuss novel materials and demonstrate applications of this technology. Two-photon-initiated chemical processes are used to fabricate arbitrary three-dimensional structures in TPS. In the first part of this article, the development of novel photoactive materials to fabricate pure inorganic or organic–inorganic hybrid microstructures is discussed. The second part discusses the fabrication of functional microstructures for highly specific applications to demonstrate the importance of TPS in different fields of science.
关键词： two-photon stereolithography,photoactive materials,functional microstructures,three-dimensional structures,TPS
更新于2025-09-23 15:21:01
-
Two Dicyanostilbene-Derived Two-Photon Fluorescence Sensors for Ag+ and Zn2+
摘要： Two-photon excitation fluorescence microscopy (TPM), which uses two photons of lower energy as the excitation source, has rapidly evolved into a widely used tool in biological and biomedical research and is popular. Compared to traditional fluorescence microscopy, TPM offers intrinsic three-dimensional (3D) resolution combined with reduced phototoxicity and photo bleaching, increased specimen penetration, and negligible background fluorescence. However, most fluorophores presently used as labels or sensor platforms in TPM belong to one-photon ones which have small two-photon absorption cross sections (δ) that limit their usage. Therefore, to make TPM a more versatile tool in biology, researchers need a wider variety of two-photon probes with large δ for specific applications.
关键词： Zn2+,dicyanostilbene-derived,sensors,Two-photon fluorescence,Ag+
更新于2025-09-23 15:21:01
-
Two-photon pumped spaser based on the CdS/ZnS core/shell quantum dota??mesoporous silicaa??metal structure
摘要： The spaser (a plasmonic nanolaser) has rapidly advanced as a subwavelength light source candidate. Herein, we introduce a spaser based on a quantum-dot, mesoporous-oxide, and metal structure from top to bottom consisting of CdS/ZnS core/shell quantum dots, a mesoporous silica film (MSF), and an Au film, respectively. Two-photon pumping using femtosecond laser pulses at 800 nm creates amplified spontaneous emission at approximately 451 nm. The advantages of MSF as a dielectric gap layer are examined through numerical simulations. Measuring the dependence of the luminescence intensity on the average pump power confirms the occurrence of two-photon up-conversion luminescence.
关键词： spaser,two-photon pumping,mesoporous silica film,plasmonic nanolaser,quantum dots
更新于2025-09-23 15:19:57
-
Editorial: Advances in Label Free Tissue Imaging With Laser Scanning Microscopy Techniques
摘要： Significant efforts are being spent at the time being for transferring various laser scanning microscopy (LSM) techniques to the realm of tissue characterization, because of their potential to circumvent some of the most important disadvantages of traditional histopathology approaches based on excisional biopsy and tissue staining. Although conventional histopathology is currently regarded as a golden standard for the diagnosing pathologies that reflect in tissular modification (e.g., cancers), limitations such as long diagnosis time, invasiveness, artifacts, sampling error, time consumption, high costs, and interpretive variability make such approaches to be impractical in many scenarios, while also placing considerable pressure on the sustainability of healthcare systems around the world. The potential of LSM techniques to contribute to overcoming these aspects derives from their “non-invasive” character. They can exploit various endogenous optical signals generated by tissues upon interaction with a laser beam and are able to provide optical sections (virtual biopsies) that reflect the tissular architecture at controlled depths. Many studies reported to date showed that LSM techniques can provide label-free information of similar pathologic relevance to the information collected for characterization/confirmation purposes with traditional histopathology approaches. These techniques are thus capable of probing optical properties of tissues with deep implications for resolving important anatomical and physiological aspects which represent hallmarks for disease predisposition and progression. To date techniques such as Confocal Laser Scanning Microscopy (CLSM) [1], Fluorescence Lifetime Imaging (FLIM) [2], Two-Photon Excited Fluorescence Microscopy (TPEF) [2–6], Second Harmonic Generation Microscopy (SHG) [5, 6], Third Harmonic Generation Microscopy (THG) [4], Coherent Anti-Stokes Raman Scattering Microscopy (CARS) [3, 7], as well as other LSM variants such as the Brillouin Microscopy [8] have already been demonstrated to be powerful tools for investigating tissue morphology, functionality, and biochemical composition with high spatial and temporal resolution. In the opinion of many, these techniques, together with investigations approaches based on their combined use, will soon become the central element of the default tissue characterization frameworks for both ex vivo and in vivo assays. Furthermore, emerging LSM techniques exploiting various ingenious strategies to achieve superresolved images in a label-free manner [9–12] are also likely to be transferred soon toward applications addressing tissue imaging.
关键词： tissue imaging,two photon excitation fluorescence microscopy,Brillouin microspectroscopy,laser scanning microscopy,second harmonic generation microscopy
更新于2025-09-23 15:19:57
-
In vivo neurovascular response to focused photoactivation of Channelrhodopsin-2
摘要： The rapid growth in the use of optogenetics for neuroscience applications is largely driven by two important advantages: highly specific cellular targeting through genetic manipulations; and precise temporal control of neuronal activation via temporal modulation of the optical stimulation. The difference between the most commonly used stimulation modalities, namely diffused (i.e. synchronous) and focused (i.e. asynchronous) stimulation has not been described. Furthermore, full realization of optogenetics’ potential is hindered by our incomplete understanding of the cellular and network level response to photoactivation. Here we address these gaps by examining the neuronal and cerebrovascular responses to focused and diffuse photostimulation of channelrhodopsin in the Thy1-ChR2 mouse. We presented the responses of photoactivation via 470-nm fiber optic illumination (diffuse) alongside 458-nm raster-scan (focused) stimulation of the barrel field. Local field potentials (LFP) assessment of intracerebral electrophysiology and two-photon fluorescence microscopy measurements of red blood cell (RBC) speed (vRBC) in cortical penetrating vessels revealed ~40% larger LFP responses (p=0.05) and twice as large cerebrovascular responses (p=0.002) under focused vs. diffuse photostimulation (focused: 1.64±0.84mV LFP amplitude and 75±48% increase in vRBC; diffuse: 1.14±0.75mV LFP amplitude and 35±23% increase in vRBC). Compared to diffuse photostimulation, focused photostimulation resulted in a ~65% increase in the yield of cerebrovascular responses (73±10% for focused and 42±29% for diffuse photostimulation) and a doubling of the signal-to-noise ratio of the cerebrovascular response (20.9±14.7 for focused and 10.4±1.4 for diffuse photostimulation). These data reveal important advantages of focused optogenetic photoactivation, which can be easily integrated into single- or two-photon fluorescence microscopy platforms, as a means of assessing neuronal excitability and cerebrovascular reactivity, thus paving the way for broader application of optogenetics in preclinical models of CNS diseases.
关键词： Thy1-ChR2,neurovascular coupling,optogenetics,two-photon fluorescence microscopy
更新于2025-09-19 17:15:36