光片显微镜是近些年来研究较多的生物成像技术，相较于传统的激光共聚焦扫描显微镜而言，光片显微镜能够实现快速、低光毒性的体积成像。光片显微镜的照明光束可以选择高斯光束或其他无衍射光束（如贝塞尔光束、艾里光束等）。艾里光片显微镜是目前研究较多的技术，但是普通的艾里光片显微镜存在一个较大的问题，艾里光束具有自弯曲的特性，导致艾里光片在视场的两端超出探测物镜的景深范围，无法发挥出最优的成像效果。将艾里光束旋转45°形成平板艾里光片，使艾里光片不超出探测物镜的景深，以增大光片显微镜的成像视场。并利用双光子荧光激发技术，免除图像的后处理过程，大大提高了成像的效率。利用Matlab进行光学仿真，得到平板艾里光片显微镜的成像视场（~900 μm）比普通艾里光片显微镜的成像视场（~600 μm）增加了50% 。搭建的平板艾里光片显微镜利用荧光微球进行校正实验，得到成像系统的横向分辨率为(1.93±0.17) μm，轴向分辨率为(3.19±0.41) μm。对斑马鱼脑出血模型的实时观测中，可以得到时间分辨率为x×y×z = 0.60 mm×0.60 mm×0.40 mm/60 s 的成像结果，并可以对局部血管的生长和发育进行实时监测，有利于脑出血疾病的机制探究。

As an attractive collector medium for hypervelocity particles, combined with outstanding physical properties and suitable compositional characteristics, SiO₂ aerogel has been deployed on outer space missions and laser shock-loaded collection experiments. In this paper, impact experiments were conducted to understand the penetration process of irregular grains, irregular Al₂O₃ grains with two different sizes and speeds (~110 μm@7 km/s, ~251 μm@2.3 km/s) at various density silica aerogels. By classifying the shapes of projectile residues and tracks, the morphology of tracks was analyzed. It was observed that there were several kinds of typical tracks in the penetration of irregular grains, accompanied by residues with the shapes of near-sphere, polyhedron, streamlined body wedge, and rotator. The rotational behavior was demonstrated by the final status of one flake projectile as direct evidence. In addition, there was no obvious relationship between the track length and experimental parameters, which may be caused by the uncertain interaction between aerogels and irregular particles. In addition, it confirmed the existence of fragmentation, melting situation by observing the shape of the impact entrance hole. At the same time, optical coherence tomography was used to observe the detail of tracks clearly, which provided a method to characterize the tracks nondestructively.

Brillouin spectroscopy is an important topic and powerful tool in modern optics, as the acquisitions of acoustic velocities and elastic moduli are one of the keys to investigate and analyze the contents of material science and condensed matter physics. Although stimulated Brillouin spectroscopy based on the pump-probe technique has striking advantages that include higher spectral resolution and signal-to-noise ratio, it is challenging to accomplish high-speed acquisition in the presence of pump background noise. In this paper, we propose a method for signal–noise separation through spiral phase precoding of the Brillouin spectrum signal. We achieve on-demand tailoring spatial distribution of the signal, and hence the signal can be separated from the background noise. Furthermore, this approach has little energy loss due to phase-only modulation, and retains the advantages of high efficiency and high gain in Brillouin interaction. The proof-of-principle demonstration provides a practical way to reshape the spatial structure of Brillouin spectra, and shows the potential in quasi-noise-free nonlinear interactions.

Black phosphorous (BP), an excellent two-dimensional (2D) monoelemental layered p-type semiconductor material with high carrier mobility and thickness-dependent tunable direct bandgap structure, has been widely applied in various devices. As the essential building blocks for modern electronic and optoelectronic devices, high quality PN junctions based on semiconductors have attracted widespread attention. Herein, we report a junction field-effect transistor (JFET) by integrating narrow-gap p-type BP and ultra-wide gap n-type β-Ga₂O₃ nanoflakes for the first time. BP and β-Ga₂O₃ form a vertical van der Waals (vdW) heterostructure by mechanically exfoliated method. The BP/β-Ga₂O₃ vdW heterostructure exhibits remarkable PN diode rectifying characteristics with a high rectifying ratio about 10⁷ and a low reverse current around pA. More interestingly, by using the BP as the gate and β-Ga₂O₃ as the channel, the BP/β-Ga₂O₃ JFET devices demonstrate excellent n-channel JFET characteristics with the on/off ratio as high as 10⁷, gate leakage current around as low as pA, maximum transconductance (g_m) up to 25.3 µS and saturation drain current (I_DSS) of 16.5 µA/µm. Moreover, it has a pinch-off voltage of –20 V and a minimum subthreshold swing of 260 mV/dec. These excellent n-channel JFET characteristics will expand the application of BP in future nanoelectronic devices.

Investigating closely stacked GaN/AlN multiple quantum wells (MQWs) by means of cathodoluminescence spectroscopy directly performed in a scanning transmission electron microscope, we have reached an ultimate spatial resolution of σCL=1.8nm. The pseudomorphically grown MQWs with high interface quality emit in the deep ultraviolet spectral range. Demonstrating the capability of resolving the 10.8 nm separated, ultra-thin quantum wells, a cathodoluminescence profile was taken across individual ones. Applying a diffusion model of excitons generated by a Gaussian-broadened electron probe, the spatial resolution of cathodoluminescence down to the free exciton Bohr radius scale has been determined.