1 Department of Photonics Engineering, Technical University of Denmark2 Nanophotonics Theory and Signal Processing, Department of Photonics Engineering, Technical University of Denmark3 Nara Institute of Science and Technology4 Nara Institute of Science and Technology
A polarization-independent, high-index contrast grating (HCG) with a single layer of cross stripes allowing simple fabrication is proposed. Since the cross stripes structure can be suspended in air by selectively wet-etching the layer below, all the layers can be grown at once when implemented for vertical-cavity surface-emitting lasers. We optimized the structure to have a broad and high reflectivity band centered at around 1xA0;x3BC;m using a finite difference time domain method, and obtained an 80xA0;nm high reflectivity band centered at 0.97xA0;x3BC;m in which the reflectivity exceeded 99.5 We also investigated the fabrication tolerances of the structure and found that, assuming careful optimizations of electron beam lithography for the precise grating width and dry-etching for the vertical sidewall, the suggested polarization-independent HCG can be fabricated using standard technologies.
Applied Optics, 2013, Vol 52, Issue 5, p. 1049-1053