Parabolic opening in atomic layer deposited TiO(2) nanobeam operating in visible wavelengths

We investigate the feasibility of developing a one dimensional photonic crystal cavity on a TiO₂ platform operating in the visible. The atomic layer deposition technique is used to finely adjust the parameters of the structure. We present the experimental demonstration of a nanobeam cavity with a quadratically tapered row of holes, in which a parabolic window is opened in order to facilitate the infiltration of gas, liquid, nonlinear material, or quantum emitters. The structure exhibits a photonic band gap between λ = 635 nm and λ = 690 nm and several resonances within the photonic band gap.