A novel method for designing crosstalk-free achromatic full Stokes imaging polarimeter

Metasurface-based polarimetry techniques have attracted lots of interests and been extensively studied in the past years,but are still hampered by narrow operating bandwidth and large crosstalk.Recently,Xian-Gang Luo's group proposed a new method of polarization-dependent phase optimization for the design of crosstalk-free,broadband achromatic,and full Stokes imaging polarimeter,which offers a promising platform for a wide range of applications including bio-photonics and integrated optics.

Application of Medical Failure Mode and Effect Analysis in Preoperative Preparation for Coronary Intervention

[Objectives]To explore application effect of healthcare failure mode and effect analysis(HFMEA)in preoperative management of coronary intervention.[Methods]The preoperative management process of 455 patients who underwent coronary intervention surgery from January to March in 2022 was sorted out,and the failure modes and causes in the preoperative management were analyzed.The priority risk value was calculated,and the top 6 failure modes were found out.Improvement measures were formulated according to the causes of failure modes.Two months after the implementation of the procedure,470 patients who underwent coronary intervention surgery from May to July in 2022 were selected as the intervention group,and the optimized preoperative preparation procedure by HFMEA was adopted.The decrease of risk priority number(RPN)and RPN value of two high-risk failure modes,as well as changes in the rate of the time of taking dual-antiplatelet drugs reaching the standard,the rate of passing the dress code,the rate of timely signing of informed consent,and the rate of filling in the handover form of preoperative preparation were analyzed.[Results]The rate of the time of taking dual-antiplatelet drugs reaching the standard,the rate of passing the dress code,the rate of timely signing of informed consent,and the rate of filling in the handover form of preoperative preparation in experimental groups were higher than those of the control group,and the difference was statistically significant(P<0.05).[Conclusions]Applying HFMEA to the management of preoperative preparation process for coronary intervention can effectively improve the timeliness and qualification rate of preoperative preparation for coronary intervention,and provide guarantee for the safe and smooth implementation of coronary intervention.

Ultra-high extinction-ratio light modulation by electrically tunable metasurface using dual epsilon-near-zero resonances

The lossy nature of indium tin oxide(ITO) at epsilon-near-zero(ENZ) wavelength is used to design an electrically tunable metasurface absorber. The metasurface unit cell is constructed of a circular resonator comprising two ITO discs and a high dielectric constant perovskite barium strontium titanate(BST) film. The ENZ wavelength in the accumulation and depletion layers of ITO discs is controlled by applying a single bias voltage. The coupling of magnetic dipole resonance with the ENZ wavelength inside the accumulation layer of ITO film causes total absorption of reflected light. The reflection amplitude can achieve ~84 d B or ~99.99% modulation depth in the operation wavelength of 820 nm at a bias voltage of-2.5 V. Moreover, the metasurface is insensitive to the polarization of the incident light due to the circular design of resonators and the symmetrical design of bias connections.

Perovskite-transition metal dichalcogenides heterostructures: recent advances and future perspectives

Transition metal dichalcogenides(TMDs)and perovskites are among the most attractive and widely investigated semiconductors in the recent decade.They are promising materials for various applications,such as photodetection,solar energy harvesting,light emission,and many others.Combining these materials to form heterostructures can enrich the already fascinating properties and bring up new phenomena and opportunities.Work in this field is growing rapidly in both fundamental studies and device applications.Here,we review the recent findings in the perovskite-TMD heterostructures and give our perspectives on the future development of this promising field.The fundamental properties of the perovskites,TMDs,and their heterostructures are discussed first,followed by a summary of the synthesis methods of the perovskites and TMDs and the approaches to obtain high-quality interfaces.Particular attention is paid to the TMD-perovskite heterostructures that have been applied in solar cells and photodetectors with notable performance improvement.Finally through our analysis,we propose an outline on further fundamental studies and the promising applications of perovskite-TMD heterostructures.

Room-temperature phonon-coupled single-photon emission in hexagonal boron nitride

Photon-lattice(phonon)coupling is fundamental to light-matter interaction,particularly when it reaches the quantum limit of the phonon-coupled single-photon emission,which holds great potential for quantum manipulation and quantum information transduction.Here,we report single defect state-phonon coupling in hexagonal boron nitride(h BN)at room temperature.An ultrabroad spectrum of single-photon emissions can be achieved by selecting the excitation energies.Using photoluminescence excitation spectroscopy,we observe single-phonon-assisted resonance-enhanced single-photon emission,along with multiple phonon replicas that herald the creation of phonon Fock state.We also develop a transition model to gain insight into the physical process behind the single defect state-phonon coupling.Our work sets the stage for manipulating electron-phonon coupling state with single quantum-level precision at room temperature.

Efficiency-enhanced reflective nanosieve holograms

Photon nanosieves,as amplitude-type metasurfaces,have been demonstrated usually in a transmission mode for optical super-focusing,display,and holography,but the sieves with subwavelength size constrain optical transmission,thus leading to low efficiency.Here,we report reflective photon nanosieves that consist of metallic meta-mirrors sitting on a trans-parent quartz substrate.Upon illumination,these meta-mirrors offer the reflectance of〜50%,which is higher than the transmission of visible light through diameter-identical nanoholes.Benefiting from this configuration,a meta-mirror-based reflective hologram has been demonstrated with good consistence between theoretical and experimental results over the broadband spectrum from 500 nm to 650 nm,meanwhile exhibiting total efficiency of〜7%.Additionally,if an additional high-reflectance layer is employed below these meta-mirrors,the efficiency can be enhanced further for optical anti-counterfeiting.

Design and fabrication of broadband ultralow reflectivity black Si surfaces by laser micro/nanoprocessing

Light collection efficiency is an important factor that affects the performance of many optical and optoelectronic devices.In these devices,the high reflectivity of interfaces can hinder efficient light collection.To minimize unwanted reflection,anti-reflection surfaces can be fabricated by micro/nanopatterning.In this paper,we investigate the fabrication of broadband anti-reflection Si surfaces by laser micro/nanoprocessing.Laser direct writing is applied to create microstructures on Si surfaces that reduce light reflection by light trapping.In addition,laser interference lithography and metal assisted chemical etching are adopted to fabricate the Si nanowire arrays.The anti-reflection performance is greatly improved by the high aspect ratio subwavelength structures,which create gradients of refractive index from the ambient air to the substrate.Furthermore,by decoration of the Si nanowires with metallic nanoparticles,surface plasmon resonance can be used to further control the broadband reflections,reducing the reflection to below 1.0%across from 300 to 1200 nm.An average reflection of 0.8%is achieved.

High Q-factor controllable phononic modes in hybrid phononic–dielectric structures

Phonon polariton resonances in the mid-infrared spectral range demonstrate properties superior to noble metal-based plasmonics,owing to smaller dissipative loss and better field confinement.However,a conventional way to excite the localized phonon resonance involves ion etching,which reduces the attainable quality factors(Q-factors)of the resonators.We show that by introducing a deep subwavelength layer of dielectric gratings on a phononic substrate,localized dipolar resonance and higher order modes with high Q-factors 96 and 195,respectively,can be excited.We further demonstrate,via experiments and simulations,that the resonant wavelength and field confinement can be controlled by coupling the localized hybrid mode with propagating surface phonon-polaritons.We also observed for the first time the coupling between a localized dipolar mode and a propagating higher-order surface phonon-polariton mode.The results will be useful in designing on-chip,low-loss,and highly integrated phononic devices in the infrared spectral domain.