Metasurfaces provide an effective technology platform for manipulating electromagnetic waves, and the existing design methods all highlight the importance of creating a gradient in the output phase across light scattering units. However, in the emerging research subfield of meta-waveguides where a metasurface is driven by guided modes, this phase gradient-oriented approach can only provide a very limited emission aperture, significantly affecting the application potential of such meta-waveguides. In this work, we propose a new design approach that exploits the difference between meta-atoms in their light scattering amplitude. By balancing this amplitude gradient in the meta-atoms against the intensity decay in the energy-feeding waveguide, a large effective aperture can be obtained. Based on this new design approach, three different wavefront shaping functionalities are numerically demonstrated here on multiple devices in the terahertz regime. They include beam expanders that radiate a plane wave, where the beam width can increase by more than 900 times as compared to the guided wave. They also include a metalens that generates a Bessel-beam focus with a width 0.59 times the wavelength, and vortex beam generators that emit light with a tunable topological charge that can reach -30. This amplitude gradient design approach could benefit a variety of off-chip light shaping applications such as remote sensing and 6G wireless communications.

分析了三传输线型脉冲压缩装置的原理，从提高功率增益和小型化角度，在脉冲压缩装置中设计了一种3起端并联绕线的内置型高阻螺旋线结构。建立电路仿真模型和三维结构电磁场仿真模型，分析了高阻螺旋线特征参数对功率增益的影响。根据优化后的结果研制出紧凑型高功率亚纳秒脉冲压缩装置，经测试，前级输入脉冲宽度8 ns，功率1 GW时，输出脉冲宽度1.5 ns，功率3.7 GW，功率增益3.7。经过30万次运行考核，装置内部无滑闪和击穿现象，验证了设计可靠性。

海面船舶目标检测一直是遥感图像处理、模式识别与计算机视觉等领域的研究热点，船舶作为海上运输载体和重要**目标，对其进行自动检测在军用与民用领域有着广阔的应用前景和重要现实意义。本文梳理了用于海面船舶目标检测的光学成像卫星的发展情况，分析了光学遥感成像船舶目标的物理特性和特征，归纳了国内外该领域海面船舶检测技术研究现状，围绕构建相关目标检测模型和架构的相关理论与关键技术进行了分析、比较和总结，探讨了当前光学遥感图像船舶目标检测方法面临的问题与挑战以及未来的发展趋势。