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

Abstract We have designed a novel metamaterial composed of LiTaO 3 /SiO 2 /VO 2 , utilizing the phase transition of VO 2 layer to facilitate a switch between bound states in the continuum (BIC) and perfect absorption. In its insulating state, VO 2 allows for tunable BIC by adjusting the asymmetry factor, achieving a high Q factor of 1.45 × 10 5 in the quasi-BIC condition. Moreover, the modulation depth of the LiTaO 3 /SiO 2 /VO 2 metamaterial can also be tuned with polarization angle, reaching a maximum value of 0.84 when the polarization is along the x -axis. When VO 2 transitions to its metallic phase, the metamaterial attains a perfect absorption of 98.74% at 4.31 THz. 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 application of multifunctional metamaterials, particularly in the fields of optical sensing, efficient light absorption, and photoelectric conversion.