A low-loss SiN photonic integrated circuit foundry platform for waveguide-enhanced Raman spectroscopy

The development of a foundry-scale waveguide-enhanced Raman spectroscopy (WERS) platform is a vital for the widespead implementation of this analytical technique. In this work we analyze the waveguide material and fabrication processes offered by AIM Photonics with regard to their effectiveness for WERS, and other sensing techniques. Optical characterization of these materials via white light spectroscopy and fluorescence spectroscopy points to the designation of an optimal wafer composition comprising a thermal bottom oxide and an LPCVD silicon nitride waveguide. This optimal composition has no measurable fluorescence and a propagation loss of 3.2 dB/m at 1064 nm in the TM00 mode. In the c/l band, the optimal wafer build has as thermal bottom oxide, a PECVD silicon nitride waveguide, and is annealed. This build has a propagation loss of 8.1 dB/m at 1550 nm in the TE00 mode.