  Octave-spanning, self-referenced frequency combs are applied in diverse
fields ranging from precision metrology to astrophysical spectrometer
calibration. In the past decade, Kerr frequency comb generators have emerged as
alternative scheme offering chip-scale integration, high repetition rate and
bandwidths that are only limited by group velocity dispersion. The recent
observation of Kerr frequency combs operating in the dissipative Kerr soliton
(DKS) regime, along with dispersive wave formation, has provided the means for
fully coherent, broadband Kerr frequency comb generation with engineered
spectral envelope. Here, by carefully optimizing the photonic Damascene
fabrication process, and dispersion engineering of $\mathrm{Si_{3}N_{4}}$
microresonators with $1\,\mathrm{THz}$ free spectral range, we achieve
bandwidths exceeding one octave at low powers ($\mathcal{O}(100\,\mathrm{mW})$)
for pump lasers residing in the telecom C-band ($1.55\,\mathrm{\mu m}$), as
well as for the first time in the O-band ($1.3\,\mathrm{\mu m}$). Equally
important, we find that for THz repetition rate comb states, conventional
criteria applied to identify DKS comb states fail. Investigating the coherence
of generated, octave-spanning Kerr comb states we unambiguously identify DKS
states using a response measurement. This allows to demonstrate octave-spanning
DKS comb states at both pump laser wavelengths of $1.3\mathrm{\,\mu m}$ and
$1.55\,\mathrm{\mu m}$ including the broadest DKS state generated to date,
spanning more than $200\,\mathrm{THz}$ of optical bandwidth. Octave spanning
DKS frequency combs can form essential building blocks for metrology or
spectroscopy, and their operation at $1.3\mathrm{\,\mu m}$ enables applications
in life sciences such as Kerr comb based optical coherence tomography or dual
comb coherent antistokes Raman scattering.
