title: High Q H1 photonic crystal nanocavities with efficient vertical emission.
abstract: We report on newly-designed H1-type photonic crystal (PhC) nanocavities that simultaneously exhibit high Q factors, small mode volumes, and high external coupling efficiencies (η([perpendicular])) of light radiated above the PhC membrane. Dipole modes of the H1 PhC nanocavities, which are doubly-degenerate and orthogonally-polarized in theory, are investigated both by numerical calculations and experiments. Through modifying the sizes and positions of the air-holes near to the defect cavity, a Q factor of 62,000 is achieved, accompanied with an improved η([perpendicular]) of 0.38 (assuming an objective lens with a numerical aperture of 0.65). A further increase of η([perpendicular]) to more than 0.60 is observed at the expense of slight degradation of Q factor (down to 50,000). We further experimentally confirm the increase of both Q and η([perpendicular]), using micro-photoluminescence measurements, and demonstrate high Q factors up to 25,000: the highest value ever reported for dipole modes in H1 PhC nanocavities.
authors.affiliation: Institute of Industrial Science, the University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8505, Japan. h-takagi@iis.u-tokyo.ac.jp
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Takagi
authors.forename: Yasutomo
authors.initials: Y
authors.lastname: Ota
authors.forename: Naoto
authors.initials: N
authors.lastname: Kumagai
authors.forename: Satomi
authors.initials: S
authors.lastname: Ishida
authors.forename: Satoshi
authors.initials: S
authors.lastname: Iwamoto
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Arakawa
mesh_terms: D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007909:Lenses; D008027:Light; D036103:Nanotechnology / Q000295:instrumentation*; D012542:Scattering, Radiation; D020349:Surface Plasmon Resonance / Q000295:instrumentation*