Design and fabrication of broadband guided-mode resonant reflectors in TE polarization

We present the design and fabrication of guided-mode resonant broadband reflectors operating in transverse electric (TE) polarization. The structure consists of a subwavelength one-dimensional grating with a two-part period and a nanometric homogeneous layer of amorphous silicon on a quartz substrate. A representative reflector exhibits 99% reflectance over a 380-nm spectral range spanning 1440-1820 nm. The fabrication involves thin-film deposition, interferometric lithography, and reactive ion etching. Experimental reflectance greater than 90% is achieved over a ~360-nm bandwidth. The spectral bandwidths demonstrated exceed formerly reported results for two-part periodic resonators working in TE polarization.