title: Polarization-independent high-index contrast grating and its fabrication tolerances.
abstract: 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 1 μm using a finite difference time domain method, and obtained an 80 nm high reflectivity band centered at 0.97 μm 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.
authors: Graduate School of Materials Science, Nara Institute of Science and Technology, Ikoma, Nara, Japan. kazikeda@ms.naist.jp
authors: Kazuhiro
authors: K
authors: Ikeda
authors: Kazuma
authors: K
authors: Takeuchi
authors: Kentaro
authors: K
authors: Takayose
authors: Il-Sug
authors: IS
authors: Chung
authors: Jesper
authors: J
authors: Mørk
authors: Hitoshi
authors: H
authors: Kawaguchi