Impact of bandwidth on field enhancements effects in finite-size dispersion-engineered metamaterials

Photonic crystals (PhC) with a degenerate band edge (DBE) or a split band edge (SBE) yield dramatic field enhancement effects due to the interplay of slow-wave effects and Fabry-Perot resonances near the band-edge frequency. Numerical simulations are performed to investigate the impact of the fractional bandwidth (FBW) on field enhancement effects in both types of PhCs. The analysis is based on an unconditionally stable finite-difference time-domain (FDTD) method. We have found out that SBE PhCs can be less sensitive to the FBW than DBE PhCs when yielding similar performance.