查看更多>>摘要：Optical microscopy has revolutionized the field of biology, enabling researchers to explore the intricate details of biological structures and processes with unprecedented clarity. Over the past few decades, significant strides have been made in tailoring optical microscopy techniques to meet the specific needs of biologists (Schermelleh et al., 2019; Prakash et al., 2022). From sample preparation to hardware designs and software requirements, improvements have been driven by the goal of enhancing imaging capabilities and facilitating quantitative analysis. The papers featured in this issue cover a wide range of topics, addressing various aspects of optical microscopy for bioimag-ing. From the application of nonlinear micro-spectroscopy techniques to explore the spatial distribution of small gold nanoparticles within multicellular organs background-free (Pope et al., 2023), to the development of a multiple feedback-based wavefront shaping method to retrieve hidden signals (Rumman et al., 2022), and the utilization of artificial intelligence and deep learning algorithms for enhanced phase recovery in inline holography (Galande et al., 2023), each study pushes the boundaries of what is possible with optical microscopy.
Christina PsaroudakiElias PeraticosChristos Panagopoulos
260501.1-260501.12页
查看更多>>摘要：Magnetic nano-skyrmions develop quantized helicity excitations, and the quantum tunneling between nano-skyrmions possessing distinct helicities is indicative of the quantum nature of these particles. Experimental methods capable of nondestructively resolving the quantum aspects of topological spin textures, their local dynamical response, and their functionality now promise practical device architectures for quantum operations. With abilities to measure, engineer, and control matter at the atomic level, nano-skyrmions present opportunities to translate ideas into solid-state technologies. Proof-of-concept devices will offer electrical control over the helicity, opening a promising new pathway toward functionalizing collective spin states for the realization of a quantum computer based on skyrmions. This Perspective aims to discuss developments and challenges in this new research avenue in quantum magnetism and quantum information.
Roberto RizzatoNick R. von GrafensteinDominik B. Bucher
260502.1-260502.13页
查看更多>>摘要：Nuclear magnetic resonance (NMR) and electron spin resonance (ESR) methods are indispensable techniques that utilize the spin of particles to probe matter, with applications in various disciplines, including fundamental physics, chemistry, biology, and medicine. Despite their versatility, the technique's sensitivity, particularly for NMR, is intrinsically low, which typically limits the detection of magnetic resonance (MR) signals to macroscopic sample volumes. In recent years, atom-sized magnetic field quantum sensors based on nitrogen-vacancy (NV) centers in diamond paved the way to detect MR signals at the micro- and nanoscale, even down to a single spin. In this perspective, we offer an overview of the most promising directions in which this evolving technology is developing. Significant advancements are anticipated in the life sciences, including applications in single molecule and cell studies, lab-on-a-chip analytics, and the detection of radicals or ions. Similarly, NV-MR is expected to have a substantial impact on various areas in the materials research, such as surface science, catalysis, 2D materials, thin films, materials under extreme conditions, and quantum technologies.
查看更多>>摘要：We report room temperature (RT) continuous-wave (CW) lasing of quantum well (QW) lasers grown on (001) Si substrates emitting at 980 nm. Two different QW structures, including conventional compressively strained InGaAs/GaAs QWs and strain-compensated InGaAs/GaAs/GaAsP QWs, were investigated. Photoluminescence properties and device performance of both structures on native GaAs and (001) Si substrates are discussed. By adding GaAsP barriers to the InGaAs/GaAs QWs, the lowest threshold current density of ridge waveguide edge-emitting QW lasers obtained on Si is 550 A/cm~2, measured on a 10 μm × 2 mm device at RT. The working temperature of the InGaAs/GaAs/GaAsP QW lasers grown on Si can be over 95 ℃ in the CW mode. This work suggests a feasible approach to improve the 980 nm laser performance on Si for monolithic optoelectronic integration.
查看更多>>摘要：A diode-pumped solid-state laser with watts-level five switchable wavelengths spanning green to red is first experimentally demonstrated. The selective wave-mixing mechanism was introduced for multiple visible wavelength switchable output. The five visible wavelengths are generated by wave-mixing of the fundamental wave, the first-Stokes wave, and the second-Stokes wave in a Nd:YVO_4 self-Raman laser. A β-barium borate crystal with a critical phase-matching angle cut is used for the wavelength conversion, and the angle-tuning method was used to achieve fast wavelength switching. A diffusion bonded YVO_4/Nd:YVO_4/YVO_4 crystal was used to reduce the thermal lens effect and increase the effective length of the Raman gain medium for high output power and efficient Raman conversion. Under a pump power of 19.5 W, five visible laser output powers achieved for the green at 532 nm, lime at 559 nm, yellow at 588 nm, orange-red at 620 nm, and deep red at 657 nm are 4.01, 1.76, 2.54, 1.41, and 2.82 W, respectively. This laser system provides a convenient way for visible wavelength-switchable coherent light generation and may find potential applications where multiple visible wavelengths are required.
查看更多>>摘要：Inserting multiple quantum wells (MQWs) into a p-n junction, Ill-nitride MQW diodes can separately function as a light transmitter, modulator, and receiver under different bias conditions. Owing to the spectral overlap between the emission and responsivity spectra, the emitted light from the transmitter is able to be modulated and detected by the modulator and receiver, which have identical MQW structures. Here, we develop a compatible fabrication process to monolithically integrate an Ill-nitride light transmitter, waveguides, Y-splitter, modulators, Y-combiner, and receiver into a tiny chip. An on-chip 405 nm light communication system is established and exhibits a transmission rate of 260 Mbps in the non-return-to-zero on-off keying scheme. The results pave a feasible route to develop sophisticated monolithic photonic circuit on an Ⅲ-nitride-on-silicon platform.
Xuan ZhangEun Chong JuJong Min LeeSung Kyu Park...
261104.1-261104.7页
查看更多>>摘要：Amorphous oxide semiconductor photodetectors (PDs) are promising ultrasensitive and power-efficient ultraviolet (UV) PDs because they generate low dark current in the dark and exhibit high photoresponse under UV irradiation owing to their superior UV absorption and pho-tocarrier transport characteristics. Herein, we demonstrate UV-sensitive and power-efficient oxide phototransistors through the nanometer-scale engineering of oxide semiconductors and appropriate modulation of gate bias conditions. The dark current and photocurrent of an oxide phototransistor exhibit a trade-off relationship in terms of the thickness of the oxide semiconductor film. Ultrathin InZnO is disadvantageous for fabricating UV-sensitive PDs because of its low photoresponse. In contrast, excessively thick InZnO is disadvantageous for fabricating power-efficient UV PDs owing to its high dark current. However, the InZnO film with an optimal film thickness of 8nm can simultaneously provide the advantages of both ultrathin and excessively thick cases owing to its low intrinsic carrier concentration and sufficient UV absorption depth. Consequently, an InZnO phototransistor with high UV-sensing performance (S_(max)= 1.25 × 10~6), low-power operation capability (I_(dark) = ～10~(-13)A), and excellent repeatability is realized by using an 8-nm-thick InZnO semiconductor and applying appropriate gate bias modulation (constant gate bias for maximized photosensitivity and temporal positive bias pulse for persistence photo-current elimination).
查看更多>>摘要：Snapshot spectral imaging aims at capturing full spatial and spectral information simultaneously. It can benefit greatly from a photon-efficient spectral decomposition that does not sacrifice spatial resolution. The multispectral filter arrays that enable compact single-chip snapshot multi-spectral imaging, however, suffer from fundamental and important limitations: low photon efficiency and low spatial resolution. Here, we introduce a spectral router for snapshot multispectral imaging to address these limitations. A spectral router routes all light incident on its entire surface directly to the photodetector of each spectral channel without need for a propagation layer between the router and the detector. Unlike filters, spectral routers do not reject light to achieve spectral selectivity and can ideally exploit 100% of the incident light. Spectral routers also break the size barrier that exists for filter arrays and can be designed with wavelength size footprint. This enables spectral routers to simultaneously provide spectral information as well as spatial information at higher spatial resolution, and can even allow them to provide spectral information without sacrificing spatial information beyond the diffraction limit. We illustrate the concept with two examples. A first spectral router covers the visible range and can achieve ideal optical efficiency for six spectral channels in a sub-micrometer footprint, which is 15 times smaller than a filter array repeat unit with the smallest Fabry-Perot filters. The second example covers the shortwave infrared (SWIR) range with nine spectral channels and is suitable for pixels that are two times smaller than the smallest SWIR imager pixels demonstrated to date.
Yifu ShiMatthew WrightMatthew K. SharpeCallum D. McAleese...
261106.1-261106.5页
查看更多>>摘要：The unambiguous detection of hydrogen in solar cell contact structures is critical to understanding passivation and degradation phenomena. Deuterium is often used to depict the distribution of hydrogen more clearly. However, experimental noise and artifacts can hinder the clear identification of species. This work provides a report of time-of hight elastic recoil detection (ToF-ERD) analysis to identify H/D contents in a thin poly-Si/SiO_x passivating contact. The structure contai() 1.3 nm interfacial SiO_x and an n~+ doped poly-Si layer with a partly deuter- ated SiN_x coating. The samples were annealed to release H/D, and ToF-ERD was used to detect H/D in monatomic, singly charged forms, without the detection artifacts associated with conventional secondary ion mass spectroscopy. Chlorine ions were used to recoil surface species, which were analyzed to clearly and unambiguously resolve H and D. Depth profiles for the recoiled Si, N, O, D, and H atoms were calculated from the energy and velocity information registered after scattering events, which enabled the analysis of the structure of the multilayer stack. Even though the surface roughness and experimental limitations cause visible broadening of the profiles, which can hinder clear detection at the interfacial oxide, the ability to resolve hydrogen-related species makes ToF-ERD a significant and promising tool for studying the role of hydrogen in the performance and degradation of solar cell passivating contacts.
查看更多>>摘要：Probabilistic Markov chain modeling of photonic crystal surface emitting lasers (PCSELs) is reported. This simulation links the scattering parameters of the photonic crystal (PC) and device level losses of the PCSEL The criteria for the conversion of the numerical model and agreement with data from the literature are discussed. We then explore the effect of increasing PC coupling coefficients and boundary mirror reflectivity on the in-plane power loss from the PCSEL. The effect of spatially varying the boundary reflectivity on the near-field is also explored.
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