Design of a programmable spiral phase mirror

Generation of optical vortices in a degenerate optical resonator with an intra-cavity spiral phase plate

We propose to generate optical vortices using a degenerate optical resonator with an intra-cavity spiral phase plate (SPP). The rays retracing skewed V-shaped paths in the resonator are phase-locked to form vortex laser with wavefront dislocation mirroring the topological charge of the SPP. Experimental demonstrations on diode-pumped solid state system using Nd:YAG crystal emitted randomly polarized optical vortices at a wavelength of 1064nm when the pump power went above 1.52W and the slope efficiency was 0.19. For long-term operations a power fluctuation of 2.2\% and pointing stability of 2.…

反对称多模波导光栅辅助窄带MZI用于可编程光谱整形单元

Anti-symmetric Multimode Waveguide Grating-Assisted Narrowband MZI for Programmable Spectral Shaping Units

提出一种基于反对称多模波导布拉格光栅的窄带马赫-曾德尔干涉仪，实现目标波段内精确传输控制及带外透明，作为可编程片上光谱整形的基本构建块。

基于自适应螺旋相位板的光学涡旋

Optical vortices by an adaptive spiral phase plate

本文提出并验证了一种基于液晶和透明电极技术的自适应螺旋相位板，通过双低电压控制实现连续相位重构，能高质量产生多种拓扑荷的光学涡旋，具有低成本、高光效和实时可重构等优势。

可编程电子光学的横向量子态表征

Transverse quantum-state characterization of programmable electron optics

本研究通过混合态叠层衍射成像技术，利用四维STEM扫描对可编程电子光学的横向量子态进行表征，发现其纯度随偏压增大而降低，且可实现器件原位校准与剂量效率提升。

Electrically reduced optical switching threshold of VO2-based THz metasurface

The VO2-based THz metasurface optical switching threshold is reduced by more than five orders of magnitude to 0.32-0.4 W/cm2 due to the supply of a subthreshold electric current. Moreover, additional deposition of Au nanoparticles can further reduce the threshold by 30% due to plasmonic effects. The proposed designs and a combined approach to controlling the sub-THz/THz transmission by electric current and light make it possible to overcome the existing bottleneck in design of dynamically programmable THz mirror array based on metasurfaces.

利用射影几何的自动光学对准

Automatic Optical Alignment Using Projective Geometry

本文提出一种基于射影几何的自动光学对准框架，利用低成本电动镜架和光电二极管优化器，实现复杂光束路径的快速、高精度对准，减少手动操作并提升可扩展性。

纳米光子波导内的可编程非线性

Programmable nonlinearity within nanophotonic waveguides

本文提出在纳米光子波导内实现可编程χ(2)全息图，通过光电导电极投影实现可重构准相位匹配，支持快速更新、闭环优化及原位诊断，规避制造缺陷并保留波导优势。

Nonorthogonal pairs of copropagating optical modes in deformed microdisk cavities

Recently, it has been shown that spiral-shaped microdisk cavities support highly nonorthogonal pairs of copropagating modes with a preferred sense of rotation (spatial chirality) [Wiersig et al., Phys. Rev. A 78, 053809 (2008)]. Here, we provide numerical evidence which indicates that such pairs are a common feature of deformed microdisk cavities which lack mirror symmetries. In particular, we demonstrate that discontinuities of the cavity boundary such as the notch in the spiral cavity are not needed. We find a quantitative relation between the nonorthogonality and the chirality of the modes …

Angular Momentum of a Photon and Phase Conjugation

Using the concept of an ideal phase-conjugating mirror we demonstrate that regardless of internal physical mechanism the phase-conjugation of a singular laser beam is accompanied by excitation within the mirror of internal waves which carry doubled angular momentum in order to match angular momentum conservation. For a Brillouin hypersound wavefront-reversal mirror this means that each elementary optical vortex belonging to a speckle pattern emits an acoustical vortex wave with doubled topological charge. The exact spatial profiles of light intensity and the intensity of hypersound in the vici…