Fig. 5: Demonstration of continuously tuned high \(Q\) factor.
From: Elastic bound states in the continuum with multi-polarization hybridization
a Dimensionless reflected energy by periodically bilateral pillars varying with height \({l}_{1}\) and frequency for \({l}_{2}/{h}_{{{\rm{b}}}}={\mu }_{2}\), when the incident angle of flexural waves satisfies \({\theta }_{{{\rm{in}}}}\cdot {l}_{2}/{h}_{{{\rm{b}}}}=28\). b Mode conversion spectra at different incident angles. c \(Q\) factors of quasi-BICs with perfect mode conversion tuned by incident angles. d, e \(Q\) factors of quasi-BICs with perfect mode conversion tuned by height deviation \(\Delta l\), under the detuning of first-first and first-second order resonances, respectively. For different deviation values, the quasi-BICs with perfect mode conversion is realized by modulating the waveguide length. f, g Dimensionless reflected energy of flexural waves versus frequency and waveguide length for \(\Delta l/{h}_{{{\rm{b}}}}=0.05\) and \(\Delta l/{h}_{{{\rm{b}}}}=13.75\).
