Design of a high-Q fiber cavity for omnidirectionally emitting laser with one-dimensional topological photonic crystal heterostructure

Design of a compact optical antenna system with high transmission efficiency utilizing a ring-like VCSEL array

Vertical cavity surface-emitting lasers (VCSELs) with gigahertz bandwidth and good beam quality possess great potential for multi-wavelength free-space optical communication. In this Letter, a compact optical antenna system utilizing a ring-like VCSEL array that can realize the parallel transmission of multi-channel and multi-wavelength collimated laser beams and has the advantages of aberration elimination and high transmission efficiency is proposed. Ten different signals can be transmitted simultaneously, greatly increasing the channel capacity. Based on the vector theory of reflection, ray tracing and the performance of the proposed optical antenna system are demonstrated. This design method has a certain reference value for designing complex optical communication systems with high transmission efficiency.

Design of a high-Q dark hollow beam cavity based on a one-dimensional topological photonic crystal

Dark hollow beams (DHBs) possess great potential for material processing, holography, and vortex beams, and thus designing a high-Q DHB cavity is significant for these applications. In this Letter, a method of designing and optimizing a high-Q DHB cavity based on a one-dimensional topological photonic crystal (TPhC) is proposed. Furthermore, how the structural parameters control the performance of the cavity is analyzed with the help of finite-element-method (FEM) simulation. According to the simulation results, the Q factor of the designed cavity can reach the order of 10⁵ with only 19 periods of layers. It is critical to mention that, although increasing the layers can improve the average Q of the cavity, it will cause serious fluctuation of both the Q factor and the divergence angle of the output beam. The design method proposed in this Letter may not only help designers of future DHB lasers but also promote the applications of DHBs in various fields.