title: Low-loss high-index-contrast planar waveguides with graded-index cladding layers.
abstract: We experimentally demonstrate, for the first time, propagation loss reduction via graded-index (GRIN) cladding layers in high-index-contrast (HIC) glass waveguides. We show that scattering loss arising from sidewall roughness can be significantly reduced without compromising the high-index-contrast condition, by inserting thin GRIN cladding layers with refractive indices intermediate between the core and topmost cover of a strip waveguide. Loss as low as 1.5 dB/cm is achieved in small core (1.6 mum x 0.35 mum), high-index-contrast (Deltan = 1.37) arsenic-based sulfide strip waveguides. This GRIN cladding design is generally applicable to HIC waveguide systems such as Si/SiO2.
authors: Juejun
authors: J
authors: Hu
authors: Ning-Ning
authors: NN
authors: Feng
authors: Nathan
authors: N
authors: Carlie
authors: Laeticia
authors: L
authors: Petit
authors: Jianfei
authors: J
authors: Wang
authors: Anu
authors: A
authors: Agarwal
authors: Kathleen
authors: K
authors: Richardson
authors: Lionel
authors: L
authors: Kimerling