  We report temporal and spectral domain observation of regenerative
oscillation in monolithic silicon heterostructured photonic crystals cavities
with high quality factor to mode volume ratios (Q/V). The results are
interpreted by nonlinear coupled mode theory (CMT) tracking the dynamics of
photon, free carrier population and temperature variations. We experimentally
demonstrate effective tuning of the radio frequency (RF) tones by laser-cavity
detuning and laser power levels, confirmed by the CMT simulations with
sensitive input parameters.
