A tunable perfect absorber based on a black phosphorus/bowtie shaped cavity hybrid metasurface

The practical application of black phosphorus (BP) is limited by its low absorption characteristics. In this work, we propose a perfect absorber based on a BP and bowtie shaped cavity, which has high tunability and excellent optical performance. This absorber effectively increases the light-matter interaction and achieves perfect absorption by using a monolayer BP and a reflector to form a Fabry-Perot cavity. We study the influence of structural parameters on the absorption spectrum and realize the adjustment of frequency and absorption in a certain range. Applying an external electric field on the surface of BP by electrostatic gating, we can change its carrier concentration to control its optical properties. In addition, we can flexibly tune the absorption and Q-factor by varying the polarization direction of incident light. This absorber has promising applications in optical switches, sensing, and slow light, which provides a new perspective for the practical application of BP and a foundation for future research, offering possibilities for more applications.

Automated summary

In this work, a perfect absorber based on a black phosphorus (BP) and bowtie shaped cavity is proposed, which exhibits high tunability and excellent optical performance. The absorption spectrum can be adjusted by changing the structural parameters, and the optical properties of BP can be controlled by applying an external electric field. The absorption and Q-factor can also be flexibly tuned by varying the polarization direction of incident light. This absorber has promising applications in optical switches, sensing, and slow light, providing new perspectives for the practical application of BP and possibilities for more applications.