  We demonstrate experimentally a new type of Bound state In the Continuum
(BIC) which is induced by the vertical symmetry breaking of a photonic crystal
slab. Such BIC emerges from the hybridization between Bloch resonances of
opposite parities once the vertical symmetry is broken, and is observed in the
vicinity of the anticrossing point at the lower hybrid band of the
energy-momentum diagram. All experimental results are nicely reproduced by
numerical simulations, and in good agreement with an analytical model based on
Friedrich-Wintgen framework. Together with the possibility of dispersion
engineering by vertical symmetry breaking, our results open the way to tailor
photonic states in the entire complex plane to study non-hermitian photonics.
