In-plane and out-of-plane band-gap properties of a two-dimensional triangular polymer-based void channel photonic crystal

Abstract

The in-plane and out-of-plane band-gap properties of two-dimensional triangular void channel photonic crystals fabricated by femtosecond laser drilling in a solid polymer material were characterized for transverse electric (TE) and transverse magnetic (TM) polarization illumination. For a 24 layer structure stacked in the Γ–M direction, the fundamental stop gap resulted in the suppression of infrared transmission of as much as 96% for TE- and 85% for TM-polarized incident light. The midgap wavelength for the TM polarization was longer by 2.5% than that for the TE polarization. Increasing the angle of incidence for both the in-plane and out-of-plane cases shifted the stop gap to short wavelengths for both TE and TM polarizations. The experimental results allowed for the estimation of the cross section of void channels and the effective refractive index of the polymer after the fabrication.