Hashemi, EhsanBengtsson, JorgenGustavsson, Johan S.Carlsson, StefanRossbach, GeorgHaglund, Asa2015-12-022015-12-022015-12-02201510.1116/1.4929416https://infoscience.epfl.ch/handle/20.500.14299/121279WOS:000361833200003In this work, the authors describe a novel route to achieve a high reflectivity, wide bandwidth feedback mirror for GaN-based vertical-cavity light emitters; using air-suspended high contrast gratings in TiO2, with SiO2 as a sacrificial layer. The TiO2 film deposition and the etching processes are developed to yield grating bars without bending, and with near-ideal rectangular cross-sections. Measured optical reflectivity spectra of the fabricated high contrast gratings show very good agreement with simulations, with a high reflectivity of >95% over a 25 nm wavelength span centered around 435 nm for the transverse-magnetic polarization. (C) 2015 American Vacuum Society.text::journal::journal article::research article