High-precision angle measurement of pulsars is critical for realizing pulsar navigation. Compared to visible light and radio waves, the wavelength of X-rays is incredibly short, which provides the possibility of achieving better spatial resolution. However, due to the lack of applicable X-ray apparatus, extracting the angle information of pulsars through conventional X-ray methods is challenging. Here, we propose an approach of pulsar angle measurement based on spatially modulated X-ray intensity correlation (SMXIC), in which the angle information is obtained by measuring the spatial intensity correlation between two radiation fields. The theoretical model for this method has been established, and a proof-of-concept experiment was carried out. The SMXIC measurement of observing angles has been demonstrated, and the experimental results are consistent with the theoretical values. The potential of this method in future applications is discussed, and theoretically, the angular measurement at the level of micro-arcsecond can be expected. The sphere of pulsar navigation may benefit from our fresh insights.

针对航空发动机电子控制器（EEC）易受高强辐射场（HIRF）干扰问题，以ZF-M600型EEC为研究对象，通过三维电磁仿真软件CST对EEC建模并进行平面波辐照仿真，模拟HIRF对EEC的干扰效应，仿真结果表明，HIRF可以通过孔缝耦合进入EEC内部并在腔体内部产生谐振，谐振频率处电场强度显著增加。依据RTCA DO-160G在400 MHz~4 GHz开展EEC辐射敏感度试验，试验结果表明：EEC失效频点为2.40 GHz和3.48 GHz，敏感模块为模拟量输入输出模块，敏感现象为模拟量数据丢失。EEC失效频点与谐振频率接近, 说明EEC失效与腔体谐振有关，在EEC内部贴装吸波材料并进行仿真，分析吸波材料的放置方式和厚度对EEC谐振电磁干扰强度的影响，仿真结果表明，贴装吸波材料可以有效抑制谐振电磁干扰。

提出了基于光强非线性响应的光致热弹光谱光强修正方法，实现了激光光强的准确修正。控制DFB激光器工作于波长调制模式，设置激光调制频率为16 369.75 Hz，通过光纤放大器增强其出射光强非线性项的幅值，光束经多次反射池后汇聚于石英音叉根部激发光热信号，采用数字锁相放大器解调得到对应的谐波信号，通过多项式拟合谐波信号背景，反演得到与浓度及光强分别对应的谐波信号。实验结果表明，当光强从22.03 mW变化至3.16 mW，谐波信号背景幅值与光强具有良好的线性关系，线性相关系数大于0.998，归一化后的谐波信号幅值波动小于0.37%。针对甲烷测量，系统在较大的浓度范围内具有良好的线性响应，谐波信号信噪比表明系统的最低检测限达0.22×10^-6。该研究为光致热弹光谱的光强修正提供了一种新的方法，可有效提高LITES系统在长期测量应用中的稳定性。

Compressing all the energy of a laser pulse into a spatiotemporal focal cube edged by the laser center wavelength will realize the highest intensity of an ultra-intense ultrashort laser, which is called the λ³ regime or the λ³ laser. Herein, we introduced a rotational hyperbolic mirror—an important rotational conic section mirror with two foci—that is used as a secondary focusing mirror after a rotational parabolic mirror to reduce the focal spot size from several wavelengths to a single wavelength by significantly increasing the focusing angular aperture. Compared with the rotational ellipsoidal mirror, the first focal spot with a high intensity, as well as some unwanted strong-field effects, is avoided. The optimal focusing condition of this method is presented and the enhanced tight focusing for a femtosecond petawatt laser and the λ³ laser is numerically simulated, which can enhance the focused intensities of ultra-intense ultrashort lasers for laser physics.

A designed visual geometry group (VGG)-based convolutional neural network (CNN) model with small computational cost and high accuracy is utilized to monitor pulse amplitude modulation-based intensity modulation and direct detection channel performance using eye diagram measurements. Experimental results show that the proposed technique can achieve a high accuracy in jointly monitoring modulation format, probabilistic shaping, roll-off factor, baud rate, optical signal-to-noise ratio, and chromatic dispersion. The designed VGG-based CNN model outperforms the other four traditional machine-learning methods in different scenarios. Furthermore, the multitask learning model combined with MobileNet CNN is designed to improve the flexibility of the network. Compared with the designed VGG-based CNN, the MobileNet-based MTL does not need to train all the classes, and it can simultaneously monitor single parameter or multiple parameters without sacrificing accuracy, indicating great potential in various monitoring scenarios.