Nonlinear optical generation and acousto-optical control of light in stoichiometric silicon nitride integrated waveguides

In this work we explored three different nonlinear optical approaches to manipulate light propagating through stoichiometric silicon nitride waveguide. In particular, we have used nonlinear optical processes for extreme spectral broadening of a short pulse injected into a properly engineered waveguides for phase amplitude modulation of the injected light and for conversion to a second harmonic wavelength.

In Chapter 3, we show our results on supercontinuum generation in low-loss, dispersion engineer Si3N4 waveguides using a commercial pulsed laser working at the C-band for optical communications. In Chapter 4, we study how the phase and amplitude of the propagating light can be changed via strain induced by surface acoustic waves in the region of the optical mode propagating through a buried waveguide. In Chapter 5, we use the coherent photogalvanic effect to create and effective second-order susceptibility grating in the amorphous, stoichiometric silicon nitride and use this grating to produce second-harmonic generation.

The work presented in this thesis shows that nonlinear optical processes can be used to control to a greater extend the properties of light in stoichiometric silicon nitride waveguides. Making use of these processes enhances the functionalities available in this platform, which is promising for many different applications, for example, high precision metrology, broadband communications and optical quantum computing.