Extended Data Fig. 2: RCWA simulations for structure tuning.
From: Directive giant upconversion by supercritical bound states in the continuum
a, Numerical band diagrams (RCWA) of the PCNS showing a FW-BIC close to the avoided crossing in momentum space (TE-like modes). b, Reflectance spectrum overlapping with the experimental absorption of NPs. c, FW-BIC displacement field intensity |D|2 in the unit cell. d, Optical energy fraction in monolayer (1L) and bilayer (2L) NPs with air and silicone superstrates. e, RCWA simulation and linear fit for spectral tuning of the FW quasi-BIC position with the lattice constant a for the radius of the circular hole r = 0.244a, thus scaling with a (other parameters fixed).