title: Sub-wavelength GaN-based membrane high contrast grating reflectors.
abstract: The GaN-based membrane high contrast grating (HCG) reflectors have been fabricated and investigated. The structural parameters including grating periods, grating height, filling factors and air-gap height were calculated to realize high reflectivity spectra with broad bandwidth by the rigorous coupled-wave analysis and finite-difference time-domain method. Based on the optimized simulation results, the GaN-based membrane HCGs were fabricated by e-beam lithography and focused-ion beam process. The fabricated GaN-based membrane HCG reflectors revealed high reflectivity at 460 nm band with large stopband width of 60 nm in the TE polarization measured by using the micro-reflectivity spectrometer. The experimental results also showed a good agreement with simulated ones. We believe this study will be helpful for development of the GaN-based novel light emitting devices in the blue or UV region.
authors.affiliation: Department of Photonics & Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu 30050, Taiwan.
authors.forename: Tzeng Tsong
authors.initials: TT
authors.lastname: Wu
authors.forename: Yu Cheng
authors.initials: YC
authors.lastname: Syu
authors.forename: Shu Hsien
authors.initials: SH
authors.lastname: Wu
authors.forename: Wei Ting
authors.initials: WT
authors.lastname: Chen
authors.forename: Tien Chang
authors.initials: TC
authors.lastname: Lu
authors.forename: Shing Chung
authors.initials: SC
authors.lastname: Wang
authors.forename: Hai Pang
authors.initials: HP
authors.lastname: Chiang
authors.forename: Din Ping
authors.initials: DP
authors.lastname: Tsai
mesh_terms: D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005708:Gallium / Q000737:chemistry*; D007909:Lenses; D008567:Membranes, Artificial; D012031:Refractometry / Q000295:instrumentation*
chemical_list: D008567:Membranes, Artificial; C473348:gallium nitride; D005708:Gallium