We propose a chip-integratable cylindrical vector (CV) beam generator by integrating six plasmonic split ring resonators (SRRs) on a planar photonic crystal (PPC) cavity. The employed PPC cavity is formed by cutting six adjacent air holes in the PPC center, which could generate a CV beam with azimuthally symmetric polarizations. By further integrating six SRRs on the structure defects of the PPC cavity, the polarizations of the CV beam could be tailored by controlling the opening angles of the SRRs, e.g., from azimuthal to radial symmetry. The mechanism is governed by the coupling between the resonance modes in SRRs and PPC cavity, which modifies the far-field radiation of the resonance mode of the PPC cavity with the SRR as the nano-antenna. The integration of SRRs also increases the coupling of the generated CV beam with the free-space optics, such as an objective lens, promising its further applications in optical communication, optical tweezer, imaging, etc.

二维材料因其独特的结构和优异的电子和光电性能，为硅基光电子集成器件提供了新的发展机遇。近年来，面向硅基光电子混合集成的二维材料探测器已被广泛研究。本文梳理了构建光电探测器的几种二维材料基本特性及其探测机制，回顾了基于二维材料的硅光子集成光电探测器研究进展，总结了其器件结构和主要性能指标。最后，讨论了进一步提升硅光子集成二维材料光电探测器性能的策略，包括大规模二维材料集成器件的制备、器件结构与金属接触界面的优化以及新兴二维材料光电探测器的探索，以期推动二维材料在硅基光电子混合集成探测器领域的商业化应用。

极化激元是光与不同极化子相互作用形成的半光半物质的准粒子，可用于亚波长尺度的光场调控，在光学成像、非线性效应增强及新型超构材料设计等领域扮演着举足重轻的角色。近年来，随着人们对转角范德华尔斯材料体系的制备工艺和物性研究的不断深入，其中许多新奇的极化激元现象也被揭示。本文综述了近年来转角范德华尔斯材料在光学领域的研究进展，包含转角石墨烯体系中的等离极化激元，转角二维过渡金属硫化物中的激子极化激元与六方氮化硼（h-BN）与 α-MoO₃体系中的声子极化激元等。最后展望转角二维范德华尔斯材料中的极化激元在纳米尺度下光与物质相互作用的有效控制方面所展现的巨大潜力。

Planar photonic crystal (PPC) cavities with high quality (Q) factors were currently designed by missing or moving air holes. Here, we propose that cutting air holes in PPC into semicircles could be considered as another strategy to realize and optimize cavities, presenting superiorities over cavities with missed or moved air holes in a higher Q factor and a smaller mode volume (V_mode). Examples are demonstrated: (1) in a PPC lattice, cutting two adjacent air holes promises a cavity mode with a Q exceeding 200,500 and an ultrasmall mode volume V_mode < 0.329(λ/2 n)³; (2) in a PPC waveguide, cutting two air holes on opposite sides of the waveguide supports a cavity mode with a Q exceeding 104,600 and a V_mode < 1.22(λ/2 n)³; (3) cutting the two air holes at the edges of an L3-type PPC cavity, the Q factor is optimized from 5500 to 124,700, with an almost constant V_mode. The concept of cutting air holes to introduce defects in PPC also promises the design of PPC also waveguides with an engineered transmission loss and dispersion.

The position-dependent mode couplings between a semiconductor nanowire (NW) and a planar photonic crystal (PPC) nanocavity are studied. By scanning an NW across a PPC nanocavity along the hexagonal lattice’s Γ – M and M – K directions, the variations of resonant wavelengths, quality factors, and mode volumes in both fundamental and second-order resonant modes are calculated, implying optimal configurations for strong mode-NW couplings and light-NW interactions. For the fundamental (second-order) resonant mode, scanning an NW along the M – K (Γ – M) direction is preferred, which supports stronger light-NW interactions with larger NW-position tolerances and higher quality factors simultaneously. The simulation results are confirmed experimentally with good agreements.