  Metasurfaces have unlocked significant advancements across photonics, yet
their efficient active control remains challenging. The active materials
required often lack continuous tunability, exhibit inadequate refractive index
(RI) changes, or suffer from high losses. These aspects pose an inherent
limitation for resonance-shifting based switching: when RI changes are small,
the resulting shift is also minor. Conversely, high RI changes typically come
with high intrinsic losses necessitating broad modes because narrow ones cannot
tolerate such losses. Therefore, larger spectral shifts are required to
effectively detune the modes. This paper introduces a novel active metasurface
approach that converts the constraint of high intrinsic losses into a
beneficial feature. This is achieved by controlling the losses in a hybrid
vanadium dioxide (VO$_{2}$) - silicon metasurface, supporting
symmetry-protected bound states in the continuum (BICs) within the infrared
spectrum. By leveraging the temperature-controlled losses in VO$_{2}$ and
combining them with the inherent far-field-coupling tunability of BICs, we gain
unprecedented precision in independently controlling both the radiative and
nonradiative losses of the resonant system. Our dual-control mechanism allows
us to optimize our metasurfaces and we experimentally demonstrate quality
factors above 200, a maximum reflectance amplitude of 90%, a relative switching
contrast of 78%, and continuous tuning from under- to over-coupling within the
infrared spectral range. This study provides a foundation for experimentally
and technologically simple, fine-tunable, active metasurfaces for applications
ranging from molecular sensors to filters and optical modulators.
