  A systematic dispersion engineering approach is presented toward designing a
III-Nitride micro-resonator for a blue/UV frequency comb. The motivation for
this endeavor is to fill the need for compact, coherent, multi-wavelength
photon sources that can be paired with, e.g., the $^{171}{\textrm{Yb}}^{+}$ ion
in a photonic integrated chip for optical sensing, time-keeping, and quantum
computing applications. The challenge is to overcome the normal material
dispersion exhibited by the otherwise ideal i.e., low-loss and
large-Kerr-coefficient) AlGaN family of materials, as this is a prerequisite
for bright-soliton Kerr comb generation. The proposed approach exploits the
avoided-crossing phenomenon in coupled waveguides to achieve strong anomalous
dispersion in a desired wavelength range. The resulting designs reveal a wide
range of dispersion response tunability, and are realizable with the current
state-of-the-art growth and fabrication methods for AlGaN semiconductors.
Numerical simulations of the spatio-temporal evolution of the intra-cavity
field under continuous-wave laser pumping indicate that such a structure is
capable of generating a broadband blue/UV bright-soliton Kerr frequency comb.
