  We propose a compact single-plasmon source operating at near-infrared
wavelengths on an integrated III-V semiconductor platform, with a thin ridge
waveguide serving as the plasmon channel. By attaching an ultra-small cavity to
the channel, it is shown that both the plasmon generation efficiency ({\beta})
and the spontaneous-decay rate into the channel can be significantly enhanced.
An analytical model derived with the Lorentz reciprocity theorem captures the
main physics involved in the design of the source and yields results in good
agreement with fully-vectorial simulations of the device. At resonance, it is
predicted that the ultra-small cavity increases the {\beta}-factor by 70% and
boosts the spontaneous decay rate by a factor 20. The proposed design could
pave the way towards integrated and scalable plasmonic quantum networks.
Comparison of the present design with other fully-dielectric competing
approaches is addressed.
