Ultraviolet perfect absorption leveraging BICs in Al/SiO2 hybrid system

Abstract

The bound states in the continuum (BICs), coupled resonance in non-Hermitian system, is typically manifested by a zero linewidth and an infinite resonance quality factor. These unique features facilitate various developments and applications in low-threshold lasers, ultrasensitive sensing, and highly efficient optoelectronics. Numerous research has been devoted to achieving perfect absorption leveraging BICs in the visible regime. For hybrid systems, it is a major issue to manipulate BICs in the ultraviolet regime. Moreover, there is currently a lack of achieving perfect absorption leveraging BICs in the ultraviolet regime. Here, a kind of Al/SiO₂ hybrid system is theoretically proposed to realize perfect absorption by motivating various types of BICs in the ultraviolet regime. In this work, the perfect absorption of 99.97% can be achieved in the Al/SiO₂ hybrid system at the wavelength of 304.4 nm. Importantly, the BICs can be modulated into the ultraviolet regime by adjusting the geometric parameters and the incident light angles, and the Q factor of 1099.4 can be successfully obtained. This work builds a theoretical foundation to realize the perfect absorption leveraging BICs for UV light detection.