Recent Advances on Nonlinear Optics in Silicon Nitride Waveguides

Nonlinear phenomena based on the material 2nd or 3rd order nonlinear susceptibility tensor χ(2) and χ(3), respectively, offer potential in a wide variety of applications by exploiting wave-mixing capabilities. The integration of these nonlinear effects at the chip scale represents the best path towards portable, compact and low power optical signal processing devices. A significant body of work has been done recently in this direction, in particular focusing on CMOS-compatible platforms. While many nonlinear effects have been demonstrated in Silicon, Silicon Nitride has recently sparked significant interest. Owing to a larger band gap, wide transparency window and low loss, the potential of SiN waveguides for linear and nonlinear optics is now well established. In this paper, we report recent results on nonlinear processes in SiN waveguides. In particular we will cover generation of an extremely broad supercontinuum extending 400 THz from the visible to 3.6 µm pumped by a turnkey telecom wavelength pulsed source. We will also report on a tunable pulse source based on dispersive wave generation in an engineered thick waveguide. Finally, we will show that SiN offers some interesting potential for χ(2) based nonlinear effects, an important step towards integrating second order nonlinearity on chip.