Transparent amorphous silicon channel waveguides with silicon nitride intercladding layer

Abstract

We have experimentally demonstrated single mode amorphous silicon channel waveguides with low optical transmission loss of 2.7±0.4 dB/cm for TE mode in the 1550 nm range. This result was achieved by using hydrogen passivation of a-Si dangling bonds and a thin, low loss silicon nitride intercladding layer prepared by plasma enhanced chemical vapor deposition between the waveguide core and the oxide cladding layer. The silicon nitride intercladding layer reduces waveguide sidewall roughness scattering and preserves the hydrogen passivation.