Low loss silicon nitride photonics for short wavelengths

Abstract

We report on development of an ultra-low loss stoichiometric silicon nitride platform for applications in wavelengths of interest to cold atom systems such as atom interferometers and clocks. Waveguide propagation loss values as low as 1.1 dB/m at λ=852 nm were achieved through a reduction in scattering and absorption losses by using a 40 nm device layer thickness and LPCVD based thermal oxide for cladding. Intrinsic Qintrisnic=44 million and loaded Qloaded=19 million is reported. Furthermore, we realize a tunable pair of Vernier ring filters with integrated thermo-optic tuning.