Brillouin and Kerr nonlinearities of a low-index silicon oxynitride platform

TL;DR

This paper investigates the nonlinear optical properties of a low-index silicon oxynitride platform, demonstrating backward SBS and FWM, which are promising for integrated photonic circuits.

Contribution

It reports the first observation of backward SBS in SiON waveguides and characterizes Kerr nonlinearity, highlighting a versatile platform for photonic integration.

Findings

Backward SBS observed with gain coefficient of 0.3 m^{-1}W^{-1}

Potential to increase SBS gain by waveguide design

Kerr nonlinear parameter measured at 0.02 m^{-1}W^{-1}

Abstract

Nonlinear optical effects including stimulated Brillouin scattering (SBS) and four-wave mixing (FWM) play an important role in microwave photonics, optical frequency combs, and quantum photonics. Harnessing SBS and FWM in a low-loss and versatile integrated platform would open the path to building large-scale Brillouin/Kerr-based photonic integrated circuits. In this letter, we investigate the Brillouin and Kerr properties of a low-index (n=1.513 @ 1550 nm) silicon oxynitride (SiON) platform. We observed, for the first time, backward SBS in SiON waveguides with a Brillouin gain coefficient of 0.3$\rm m^{-1}W^{-1}$, which can potentially be increased to 0.95$\rm m^{-1}W^{-1}$ by just tailoring the waveguide cross-section. We also performed FWM experiments in SiON rings and obtained the nonlinear parameter $\gamma$, of 0.02 $\rm m^{-1}W^{-1}$. Our results point to a low-loss and low-index photonic integrated platform that is both Brillouin and Kerr active.