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Microdisk lasers are important components in photonic integrated circuits (PICs), of which the whispering gallery modes (WGMs) are usually confined within a two-dimensional (2D) planar slab. Here, owing to the strain relaxation of quantum wells by wet-etching method, we present ultra-thin curved visible microdisk lasers with single-mode lasing emission and a high quality factor of ∼17,000, which enable a 3D spatial intensity distribution of WGMs and provide an extra degree of freedom for the confined photons compared with the conventional 2D in-plane WGMs. The curved microdisk lasers with a 3D spatial profile of WGMs may provide attractive applications in flexible and multilevel photon sources for the PICs.

In this Letter, we present long-wavelength microdisk lasers based on five stacks of self-assembled InAs/InAlGaAs quantum dots as the active medium, which were grown on InP (001) substrate by solid-source molecular beam epitaxy. The 8.4-μm-diameter quantum dot microdisk laser is operated at room temperature under pulsed optically pumping conditions. Multi-wavelength lasing emissions at ∼1.6 μm were achieved with a low lasing threshold of 30 μW and a quality factor of ∼1336. The lasing behavior was verified by the "S" shape L–L curve, linewidth narrowing effect, and strong speckle patterns of the collected near field intensity profile. The demonstrated long-wavelength lasers with low threshold and ultracompact footprint can find potential applications in integrated gas detection and highly localized label-free biological and biochemical sensing. [ABSTRACT FROM AUTHOR]

Aims: Immune cell alterations may play a role in the development of atrial fibrillation (AF). Our objective was to comprehensively characterize immune cells in AF, and investigate the potential mechanisms., Methods and Results: Single-cell RNA sequencing and multicolor flow cytometry revealed that T cells constituted the most significant subset alterations in AF, and senescent CD8+ T cells were AF-associated subset. Senescent CD8+ T cells increased in both peripheral veins (p < 0.0001) and the left atria (p < 0.05) in patients with AF compared to non-AF control. Senescent CD8+ T cells were independently associated with AF prevalence (odds ratio = 2.876, p < 0.05) and postprocedural recurrence (hazard ratio = 22.955, p < 0.0001) using a cross-sectional study and a subsequent prospective cohort study. Senescent CD8+ T cells secreted an increased amount of interferon (IFN)-γ, which induces Ca2+ handling abnormalities in human induced pluripotent stem cell-derived atrial cardiomyocytes, and translated into an increased susceptibility to AF assessed by heart optical mapping., Conclusions: An increased amount of senescent CD8+ T cells may be a hallmark of the immune senescence phenotype in AF and potentially serve as a valid biomarker for assessing prevalence and postprocedural recurrence of AF. By connecting immune senescence with electrophysiological disturbances in AF, this research provides a potential mechanism for the involvement of senescent CD8+ T cells in proarrhythmic calcium disorders and suggests novel avenues for developing new immune-modulatory and senolytic therapies for AF., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Recently, all-inorganic halide perovskite quantum dots have become a very promising material for light-emitting diodes. Herein, we demonstrate a facile method, namely, layer-by-layer spin-coating of CsPbBr 3 QDs to improve device performance. After optimization of the number of emissive layers, the maximum EQE can be increased from an initial value of 0.69% to 2.31%. Additionally, we inserted a CBP layer between PEDOT:PSS and CsPbBr 3 multilayers to balance charge transportation and recombination. As a result, a 37% improvement in EQE (up to 3.16%) and highest luminance of 2629 cd m -2 are obtained., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

A flexible photonic crystal cavity, consisting of a III-V active layer embedded in a flexible medium, with a line-defect by removing three air holes for nanoscale structural deformation detection is proposed and optimized. The cavity can hold the photonic band-gap modes with the fundamental mode located at approximately 686 nm, overlapping with the photoluminescence spectrum of the InGaP/InGaAlP quantum wells. Results of finite-difference time-domain simulations indicate that the L3 cavity features an ultra-compact mode volume of 10 -3 µm 3 and high quality factor of 10 4 at a sub-micron footprint within the studied visible wavelength. Theoretical optical strain sensitivities of approximately 4.5 and 3 nm per ε (1% strain for both) for the x and y directions are predicted, respectively. When the cavity is under large bending curvatures, the Q factor rapidly decreases from 8000 to 2000.