Perfect Poincaré beams (PPBs) are highly esteemed for their topological charge-independent radius and intensity profile. However, the generation and

Perfect Poincaré beams (PPBs) are highly esteemed for their topological charge-independent radius and intensity profile. However, the generation and manipulation of PPBs typically involve two-dimensional planes perpendicular to the optical axis, hindering broader usability. Here, leveraging a single-layer all-dielectric geometric metasurface platform, we numerically showcase the generation and manipulation of multiple multidimensional PPBs. Multiple dimensions of PPBs, involving orbital angular momentum (OAM), polarization state, and three-dimensional (3D) spatial propagation, can be manipulated independently via tailoring topological charges assigned to two orthogonal perfect vortex beam (PVB) components, varying initial phase difference and amplitude ratios between two orthogonal PVB components, and strategizing 3D propagation trajectories. To demonstrate the feasibility of the recipe, two metasurfaces are designed: one is for generating an array of PPBs with tailored polarization states along cylindrical helical trajectories, and the other is for creating dual arrays of PPBs with personalized OAM and polarization eigenstates across two misaligned focal planes. As a proof-of-concept illustration, we showcase an optical information encryption scheme through a single metasurface encoding personalized polarization states and OAM in parallel channels of multiple PPBs. This work endeavors to establish an ultra-compact platform for generating and manipulating multiple PPBs, potentially advancing their applications in optical encryption, particle manipulation, and quantum optics.show less

With the urgently increasing demand for high-speed and large-capacity communication transmission, there remains a critical need for tunable terahertz (THz

With the urgently increasing demand for high-speed and large-capacity communication transmission, there remains a critical need for tunable terahertz (THz) devices with multi-channel in 5G/6G communication systems. A magnetic phase-coding meta-atom (MPM) is formed by the heterogeneous integration of La:YIG magneto-optical (MO) materials and Si microstructures. The MPM couples the magnetic induction phase of spin states with the propagation phase and can simultaneously satisfy the required output phase for dual frequencies under various external magnetic fields to realize the dynamic beam steering among multiple channels at 0.25 and 0.5 THz. The energy ratio of the target direction can reach 96.5%, and the nonreciprocal one-way transmission with a max isolation of 29.8 dB is realized due to the nonreciprocal phase shift of the MO layer. This nonreciprocal mechanism of magnetic induction reshaping of wavefront significantly holds promise for advancing integrated multi-functional THz devices with the characteristics of low-crosstalk, multi-channel, and multi-frequency, and has great potential to promote the development of THz large-capacity and high-speed communication.show less

Optical vortices, characterized by their infinite orthogonal eigenmodes—such as orbital angular momentum (OAM) and cylindrical vector beam (CVB) modes—off

Optical vortices, characterized by their infinite orthogonal eigenmodes—such as orbital angular momentum (OAM) and cylindrical vector beam (CVB) modes—offer unprecedented opportunities for advancing optical communication systems. The core components of these systems—mode (de)modulation, mode processing, and mode transmission—are fundamental to the construction and networking of OAM/CVB mode-based communication networks. They significantly influence signal encoding, enhance channel capacity, and facilitate signal interconnection and transmission. We explore the historical development and recent advancements in optical vortex-based communication systems from these three critical perspectives. We systematically summarize the normative definitions and research progress related to key concepts such as mode multiplexing and routing. We also demonstrate the performance of these systems in terms of communication capacity, bit error rate, and more. Furthermore, we examine the substantial challenges and future prospects in this field, with the aim of offering cutting-edge insights that will facilitate the advancement and practical implementation of optical communication networks leveraging optical vortex modes.show less

Accurate characterization of high-power laser parameters, especially the near-field and far-field distributions, is crucial for inertial confinement fusio

Accurate characterization of high-power laser parameters, especially the near-field and far-field distributions, is crucial for inertial confinement fusion experiments. In this paper, we propose a method for computationally reconstructing the complex amplitude of high-power laser beams using modified coherent modulation imaging. This method has the advantage of being able to simultaneously calculate both the near-field (intensity and wavefront/phase) and far-field (focal-spot) distributions using the reconstructed complex amplitude. More importantly, the focal-spot distributions at different focal planes can also be calculated. To verify the feasibility, the complex amplitude optical field of the high-power pulsed laser was measured after static aberrations calibration. Experimental results also indicate that the near-field wavefront resolution of this method is higher than that of the Hartmann measurement. In addition, the far-field focal spot exhibits a higher dynamic range (176 dB) than that of traditional direct imaging (62 dB).show less