Dynamic modulation from BIC to perfect absorption with LiTaO3/SiO2/VO2 metamaterials

Abstract We have designed a novel metamaterial composed of LiTaO3/SiO2/VO2, utilizing the phase transition of VO2 layer to facilitate a switch between bound states in the continuum (BIC) and perfect absorption. In its insulating state, VO2 allows for tunable BIC by adjusting the asym-metry factor, achieving a high Q factor of 1.45×105 in the quasi-BIC condition. Moreover, the modulation depth of the LiTaO3/SiO2/VO2 metamaterial can also be tuned with polarization angle, reaching a maximum value of 0.84 when the polarization is along the x-axis. When VO2 transitions to its metallic phase, the metamaterial attains a perfect absorption of 98.74% at 4.31THz. Notably, the resonant peak of our design is sensitive to various surrounding mediums, and it achieved a maximum figure of merit (FOM) of 584.52 RIU-1, displaying exceptional sensing capabilities. Therefore, our work provides a novel approach to the design and applica-tion of multifunctional metamaterials, particularly in the fields of optical sensing, efficient light absorption, and photoelectric conversion.