Quasi-BIC sharpening narrowband meta-holography in the visible regime

Nonlocal meta-optics have attracted tremendous attention for their exceptional light-field control capabilities enabled by ultrahigh quality-factor (Q-factor) resonances. As the nonlocal effects strongly rely on the spatial consistency of nanostructures, existing nonlocal metasurfaces primarily enable basic wavefront shaping functions, such as focusing, but lack the arbitrary phase encoding capability of constructing high-Q holography. Here, we experimentally realize the quasi-bound states in the continuum (q-BICs)-sharpened narrowband meta-holography in the visible regime. By quantitatively evaluating the q-BIC tolerance for random disturbances and strategically minimizing abrupt phase variations with a phase-smoothing strategy, spectrum-selective meta-holography is successfully realized, with its bandwidth sharpened by q-BIC (Q-factor > 89) centered at ∼642.4 nm. Such q-BIC-sharpened complex wavefront encoding is an attempt to realize high-Q meta-holography, effectively suppressing off-resonant crosstalk under broadband illumination. These findings potentially open new avenues for nonlocal wavefront shaping and numerous applications, including next-generation displays, spectral sensing, and emitting systems.