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.