Kerr nonlinearity induced four-wave mixing of CMOS-compatible PECVD deposited ultra-Si-rich-nitride

Benefitting from low propagation loss and complementary metal–oxide–semiconductor compatibility, Si 3N 4 is heavily explored for the applications of nonlinear optical signal processing. However, the Si 3N 4 waveguide is limited by its low optical Kerr nonlinearity. In this work, we introduce highly nonlinear ultra-Si-rich-nitride (USRN) deposited by the plasma enhanced chemical vapor deposition system. The measured linear refractive index of USRN is 3.09 at a wavelength of 1550 nm, while the Kerr nonlinearity of the USRN waveguide is experimentally extracted with a value of 2.25 × 10 − 17 m 2/W. Moreover, a broadband wavelength conversion ranging from S-band to L-band by a four-wave-mixing experiment is realized via designed USRN waveguide with a relatively short length of 3 mm. The measured bandwidth is 190 nm with a continuous-wave pump laser located at 1530 nm. The conversion efficiency is measured approximately − 48 dB under a relatively low pump power of 7 dBm.