  The nonlinear propagation of optical pulses in dielectric waveguides and
resonators provides a laboratory to investigate a wide range of remarkable
interactions. Many of the resulting phenomena find applications in optical
systems. One example is dispersive wave generation, the optical analog of
Cherenkov radiation. These waves have an essential role in fiber spectral
broadeners that are routinely used in spectrocopy and metrology. Dispersive
waves form when a soliton pulse begins to radiate power as a result of
higher-order dispersion. Recently, dispersive wave generation in microcavities
has been reported by phase matching the waves to dissipative Kerr cavity (DKC)
solitons. Here, it is shown that spatial mode interactions within a microcavity
can also be used to induce dispersive waves. These interactions are normally
avoided altogether in DKC soliton generation. The soliton self frequency shift
is also shown to induce fine tuning control of the dispersive wave frequency.
Both this mechanism and spatial mode interactions provide a new method to
spectrally control these important waves.
