  Much progress, both experimentally and theoretically, has recently been made
towards optical frequency comb generation from continuously pumped second-order
nonlinear systems. Here, we present the first observations towards finding an
integrated solution for such a system, using a titanium indiffused lithium
niobate waveguide resonator. These results are compared to recently developed
theory for equivalent systems. The system is seen to exhibit strong
instabilities, which require further investigation in order to fully determine
the suitability of this platform for stable optical frequency comb generation.
